scoring and restricting class'

hello, sorry for the newb questions...
1)I would like to know how to make an object, that when damaged, adds a score to a specific team...
2)i would also like to know how to force all players to join as a specific class,
3)and how to force that class to use a specific weapon...(can this work, even if they dont have that specific weapon? ex. like changing all sniper rifles to huntsman?)

thanks so much for reading this...