As POA are you responsible and liable for any charges or costs they incur or is the senior responsible?

I was POA for my mother for four years, and according to the attorneys I dealt with regarding an existing law suit against her when I began, I was a very good one! I worried about such matters, since I needed to not only help my mother pay her bills, but also handle the fallout of years of her poor business dealings. I can tell you, absolutely, that a POA is not responsible for the principal's financial dealings, past or current, as long as those actions are performed independently by the principal and are outside of your control. For example, if my mother wanted a Visa card opened, and if I took care of opening it for her but was NOT a joint holder of that account, any errors or overuse of the card was NOT my responsibility. Even if I was an "authorized user" who had to buy her groceries, etc. with that account. Had I been her Guardian, that would be different! In those cases, you might be held responsible for things if you knew about them, but even then, it's not likely.
The job of a POA is to perrform such activities that are directed BY the principal, on their behalf, and that's all there is to it. Please be careful to keep receipts for any transactions you perform on their behalf; i.e. if you write and sign a check to a drugstore when picking up Rx's, be sure to keep the receipt that backs up the check amount. I also live in Indiana, and although it is correct that all POAs here are "Durable," that does not mean that they cannot be revoked by the principal - so, they would not last "until death" in the case of a revocation.
Don't be afraid of the POA! It is a very useful tool for being able to help a parent! Especially since the Privacy Act makes it virtually impossible to discuss their affairs otherwise. Yes, you can get one online, but an attorney usually doesn't charge much, and your questions can all be answered in a way that makes you feel safer. Also, your father might feel better signing it in front of a lawyer, and having his own questions answered. Plus, your father is responsible for paying the attorney, so might also use that opportunity to formulate his Healthcare Representative and Living Will papers, along with any estate issues he wishes to discuss privately. My mother did all of those things, and wrote her Will at the same time, and I think the entire bill for all services was $500, and this was a reputable estate planning firm.
My mother later got scammed by a nursing home employee who convinced her to revoke my POA (I have a long thread about that on this site!), but even so, while I was her POA it made everything very easy and I had no problems with anything I tried to get done, including her banking. By the way, Canada is not the only country to watch these transactions and report them as elder abuse when needed. When the scammer started taking my mother to the bank, before having me revoked and becoming her new POA, the bank reported everything to their Security Department who kept me advised and documented everything for Adult Protective Services. If you are always honest in your dealings, as I was, the bank and everyone else will know it and help you as much as they can with whatever you need to get done. GOOD LUCK! None of this is easy!

You are responsible for paying encumbrances out of THEIR funds, not your own. You are an agent able to top business for them. But you are not liable for their debts, unless they are debts you take on on their behalf.

As POA, I never took care of any dealings until my mother could no longer take care of them herself. Keep excellent records of everything that you do. After her death, the family was concerned that I abused the power. I had all the records that I needed to show how everything was spent and had to request copies of paperwork that she completed even years before her illness. It amazes me how no one is ever worried while the loved one is sick and needs help but when they are gone and people think there may be some money involved, they come out of the woodwork. I wish they cared for her as much as they worry about her money. She was in a nursing home for 5 years so I don't know how much they would think she would have left....Anyway, I would care for her and love her and do everything that I have done for the past 12 years without the help of anyone else.....I would do it again and again. I can sleep at night because I know I gave her all the love and respect that she had given me for years and she died with dignity.....

In addition to a POA, another idea that might be helpful is to get an Authorization to Release form signed by your father. That way Healthcare, Medicare, insurance companies, etc.can disclose information to you. To do that, it's best to get a form from each provider; some forms may be available on their website. There are standard templates out there, but I've found that each entity only allows their "own" form. Good luck.

Respite care is most definitely OKAY to pay for with the principal's funds, as long as the principal (the person naming you as POA) agrees to it - and if they are going, and enjoying the place, then that constitutes agreement also. Paying for ANYTHING that the principal wants and/or agrees to, assuming the person has not been determined incompetent and you are in no way taking advantage, is FINE. You must not "fear the POA" as a useful tool! You are merely helping the person/parent, and if they willingly agree in these decisions and are never forced to agree, you are simply "acting on their behalf" and acting according to their agreement/instructions. That is the role and purpose of a POA. If the prinicipal appointed you, then they are trusting you to act in their best interests and according to their wishes, even though at times they may be slightly hazy about the details. Believe me, they'll let you (and everyone else) know if they object to your actions, at which time you need to respond to their instruction. When and if that happens, you may have to switch to Guardianship (if appropriate), so that you can make those decisions for them, because they are unable.

My husband is POA for his mother. He made the decision to step in when she could no longer manage on her own. One problem which did occur. His mother refused to stop driving, even though the state of PA took her license away. When he found out he could be held liable as POA, because he knew the license was revoked and she continied to drive, we ultimately had to put the club on her car.
As far as being financially responsible for another's purchases, unless you co-sign you are not responsible. I would suggest if the person you are POA for, you and them sit down and make a spreadsheet of expenses to compare what is coming in and what is going out. There are greedy and selfish wolves who may try and take advantage of the elderly.... even family members which we have seen in my husband's family. Plus, a strict budget may be needed if you plan to have homecare.
As my mother in laws Alzheimers has progressed, and my husband needed to cash in investments for her care, my husband experienced roadblocks by various financial institutions. They would not honor the POA. Some of the companies did not want to give up "her" money and made it very hard.
There is a huge difference between having a POA and having guardianship.
Hope this info helps!

Can you consider the Respite Care Activity outside the house as assets being used from her money for her best of her interest even if it is for the caregiver too?

Thanks and thank the Lord she went along and she actually enjoyed herself. I was so happy seeing her enjoying her self with other people around her age when she first thought she would not. I do beleive this will be very beneficial for her in many ways. She can connect to others of what they are going through the illness n she can feel she has indenpendecy, friends and selfworthy. Now, if i can get the stupid doctor to sign the form saying she okay n what limiatation she may have so she can go again.
Thanks again

Thank you everyone so much for your advice and experiences. I have two state-specific (Texas) power of attorney forms I purchased from US Legal Forms. (One is called "Statutory Durable Power of Attorney and the other one is called " Texas General Durable Power of Attorney.") I think I might contact an attorney to see which one would be best and further put my mind at ease.

As part of the document package, Dad has his Will and his Living Will all set up and done. The POA is the only thing I don't understand fully. Hopefully a lawyer won't cost too much, since I already have the forms. This will make things much easier, so I don't have to have my dad sign stuff and make him give authorizations over the phone all the time. He hates doing that stuff anyway and would rather not have to do it.

Laws etc may be different there (I am from Aus) but I would expect that as a general rule you are not responsible for their debts. However, if you chose to incurr a debt on their behalf knowing that they cannot pay it you might be held responsible. Also, you are probably legally bound to make the best decisions for them so there is a chance (my opinion only though) that you would be legally accountable for any decision you make... But (for example) if they owed money on their home and died without being able to pay that, then as a rule I wouldnt expect that you would be liable for the debt due to being POA...