You and your wife live together abroad. No need for any affidavits from friends. When you study instructions, do it carefully. You are reading from a list that is preceded by the words, "In addition to the required....." and "one or more of". Nothing on that list is required, and "one or more" does not mean "all". Just show your address history is the same, and maybe your resident status evidence showing you are together and skip anything you don't have or can't easily provide.
The financial sponsorship issue isn't going to come up for a year or so. Deal with it then, based on the facts at that time. Current income is the KING in that regard.