1) You could've joined when you sent your 6 games in, but now you can email the company -
www.ra-fa.co.uk
2) You can get all sorts! Whistles, match pads, lanyards, towels with FA Badge embroidered, kit, badges, touchline flags, watches, FA Memory sticks - you get the message, all sorts!
3) Things cost different amounts - some things are relatively cheap, others are quite expensive
4) You get different number of points per game dependant on how many games you do in a season - if you do 40 games or less, you get 20 points per game. If you do 41-60 games in a season, you get 30 points per game.
5) You can still get the points for games you've done this season, you'd need to find the managers, although you can use league/county representatives for some games, not all.
Hope this helps