For the kills to cash, there is an easy method that works flawlessly.
The catch is that you have to make a lot of seperate triggers, like this:
Player gets 5 kills, add 2 minerals.
Player gets 15 kills, add 2 minerals.
Player gets 20 kills, add 2 minerals.
Player gets 25 kills, add 2 minerals.
Player gets 30 kills, add 2 minerals.
Player gets 35 kills, add 2 minerals.
etc.
Luckily, there is a program called
SCTrigger that can generate these triggers for you.
QUOTE(funkmu)
Also, is there a way to make comp players on different forces part of ur allies?
Yes. Use the trigger action called "Set Alliance Status" and ally the players with eachother.
You can also make the players give shared vision to eachother using the "Run AI Script" action.