Can you functionally do it? Sure.
But what you should really consider is everything that COULD go wrong in the next four or five decades, and the impact that it could have on your friendship.
What if your friend could not pay his/her portion of the annual dues?
What if you have a disagreement about the usage of the points? With both of your names on the contract, technically EITHER of you could call and make a reservation. How would you respond if you called and found out that your friend used points outside of your handshake agreement?
What would happen if either of you passed-away? From research we did during our purchase, it's my understanding that by Florida law, if both of your names are on the deed and one of you should die, full ownership would pass to the surviving owner.
Other people have made good suggestions about 100pt resales. If you want to combine points from two contracts to book a single stay, it's very easy to do.