Once you've chosen a rifle, shotgun, assault rifle, or SMG, (look at my suggestion for a still simple but good weapon system) then you should be able to choose a side weapon.

There should be 4 side weapons

1. 5 grenades instead of 2

2. Medic (you'll have a medikit that you can heal other people on your team with at a maximum range of 10 blocks, so being a medic would really help out squads)

3. Pistol, basically rifle except half everything. Good for if you're using an SMG

4. Drill (faster tool for griefing)

Might want to provide a link to that thread in your OP, OP.
Also, we don't need a faster tool for griefing. That's counter-intuitive.

these don't seem too bad, the only thing is the range seems kind of high for the medkit, and the drill is pretty much the same as the pickaxe, unless you make it some large drill. but cool ideas, it is good to see that people are thinking about things