Is it permissible to address an elderly man or woman as "father" or "mother" out of love and appreciation, knowing that adoption is forbidden? And is it permissible for a person who intended to donate money as charity to retract their intention and reclaim the money?

There is no harm in repeating words that convey respect and affection, such as "O my son" and "O my uncle," because it falls under the rubric of veneration and mercy, which are enjoined by Islamic law. It has no relation to the prohibition of adoption. As for donating money, if someone intends to give money in charity but then changes their mind or decides to spend it on themselves or on something else, there is no harm in that.