As host to many a home game, weekly for last 20 years, I'll say that:
a) He the player was not required too split the jackpot.
b) Your willingness to back these players is to keep your paying customers happy.
c) You should not back players, it sacrifices the integrity of play for the paying customers.
d) You should not even lend money. I've seen many friendships destroyed at a poker table over a $100.00 loan.
My story, explanation. We were palying cash games, and I would occasionally "back" a player, everybody was aware and had no problems with it. New player starts to play regularly, and comments that me losing to "backed" player screws with the odds for other players, because any loss to "backed" player will get me back half my bets, and "backed" player plays looser cuz she had nothing to lose. Everyone jumped on his bandwagon and that had to stop. Instead, I started lending money, not backing. The list got long, as I kept it on paper. I could go on, but the moral of the story is, "if you can't pay, you can't play!". The weekly game has now turned into quarterly (4x/yr.).