Re: Sam’s family, my understanding from various reviews is that they actually lifted large parts of
Anthony Mackie’s history for Sam. I also gather he’s a little annoyed they wouldn’t let him eat a crayfish on screen. Can’t say I blame him there, would it really have broken the budget Disney?
Re: money, they both also have the added complication of having been on the run for however long it was between Captain America: Civil War and Infinity War. Even if Stark gave everyone a salary, I can’t see him continuing it after the airport battle.
That said, they must have been getting money from
somewhere, because Steve had his own apartment in Winter Soldier. Military back pay maybe?