For example: If someone is willing to help in a transaction and I am willing to pay for it. Is it okay or legal that I sign the power of attorney and have them do the transaction or speak on my behalf?
It's legal but I caution you as to what type of POA it is, as it can very easily be misused!
You don't need a power of attorney for that and should not sign one. A power of attorney gives an individual the rights to speak for you in ALL matters. They have access to your bank accounts, records, etc. What you need in this case is a very specifically worded document authorizing a single transaction, which must be notarized and witnessed.
