Have all characters start at a certain health and with a bit of working around you can get scripts working in MP.
When they choose a class have it set a variable... for simplicity I'll call it the "Class Var".
How to set certain health levels:
Based upon which value the Class var is set to, decrease the players health to the desired level.
How to only let certain classes pick up certain weapons:
Each weapon will have a different pick up script that checks for a specific Class Var value in order to allow the player to pick them up.
TADA!
The one and only,
Whosoever says, "Don't sweat the small stuff," is obviously not a programmer.