One word answers all your qwestions:
S E A R C H !!!
Anyway, i'm going to help you, on some:
1. Use search
2. In the corrent version of FPSC you can only have 1 MP map, There are out there lot's of apps. so they show a windows screen and you choose the map you want to play, it then will load that exe (wich is going to be the map). You can also do it yourself with a app. like Flash.
3. a) There isn't location damage (no hitboxes) and there most likely never will.
b) Everything is in the menu when you right click the weapon (after it's placed on the map), also, that menu is called propreties or wtf. I also suggest you try out the various scripts that are in hte script bank, all the ones with amm/weapon in their name.
Hope it helps, if it didn't, please, use search next time
Peace
My love is seperated in 2 parts, 1 of them is 3ds Max 7, the other; FPSC.