1) When you deposit points in the bank it does say there is a fee and that there is interest. I decided to remove the fee though so that no longer will apply.
2)Points have three purposes. You can use them to purchase stuff from here
http://www.retrouprising.com/index.php?action=shop. Some contest require them as entry fees and they go into the prize pot that the winner will take. And they are mainly just like points in a game just there so you can say how many points you got and compare yourself to others.
3) You get points for posting, winning contests and getting First, Second or Third place in a game.