Well I can help you with some of the scripts. I mainly mod KOTOR 2, but I believe most of the scripts work the same.
1. This script should turn the recruit hostile.
void main(){
object oNPC1 = GetObjectByTag("recruit");
ChangeToStandardFaction(oNPC1, 1);
}
2. Do you mean after a certain amount of time, or after they reach a certain amount of health?
3. This should work.
void main()
{
RemoveAvailableNPC(7);
AddAvailableNPCByTemplate(7, "templatename");
DelayCommand(1.5,ShowPartySelectionGUI());
}
Be aware though that you will have to replace another member of the party, unless it's say Juhani and you never picked her up. You should also set the 'tag' of the the recruit to whoever you're replacing to avoid some issues.
The seven should be set to the corresponding slot of the person you're going to replace.
4. Try :
void main()
{
AdjustAlignment( GetFirstPC(),ALIGNMENT_LIGHT_SIDE,80);
}
If you get stuck on scripts, I highly recommend this thread:
http://www.lucasforums.com/showthread.php?t=143412). I actually have it bookmarked.
Hope all that helps.