I've found these configs to suit me, I prefer to just use my left hand mainly for movement and dodging so rather not have it tied up with abilities. The abilities are in their places to match their style as well. 3= health boost, Shift=Utility, Mouse 3= high damage
Soldier
1. Short range SMG
2. Short very fast shotgun
3. Heal
4. Bandage
5. Wrench
Shift. 6th Sense
Mouse 3, side mouse button. Grenade Spam
Mouse 2, wheel mouse click. Burning Bullerts
RMB. Blasting Strike
Gunner
1. Long range Machine gun
2. Short range shotgun
3. Shield
4. Bandage
5. Wrench
Shift. Leg It
Mouse 3, Keg
Mouse 2. IEG
RMB. Rocket Launcher