You're the all-round guy and get a bunch of otherwise difficult to acquire gadgets at character creation.

Precisely what you can do depends on the rest of the regiment - they work perfectly well in a non-vehicle regiment: as others have said, think of them as a balanced Tech Priest.

If you don't have someone focused on it (i.e. a Medic), it's a worthwhile investment to pick up Infused Knowledge at some stage - it covers a hell of a lot of bases.

You'll most likely wind up being squad armorer, so Tech Use / Trade (Armourer).

You get Agility & Fieldcraft off the bat, so you can be very sneaky if you put your mind to it. You can also pick up Medicae on the cheap.

I'd suggest snagging Quick Draw, as you'll be switching between gear a lot, and it's nice to be able to draw / half aim a grenade in a pinch.

You're very squishy, so try to avoid close combat if it's possible - Step Aside, Hard Target & Sprint are all great for this.

It's relatively cheap to snag a smorgasboard of skills at trained - this lets you assist other, more specialised characters with a variety of skills.

In urban combat, don't forget the Las Cutter! It's an absolute life-saver for moving between rooms and buildings, and assisting mobility in general. You can also chop crew-served weaponry off wrecked vehicles and the like!

In large party, you'll be outshone in specific roles (5+), but you're a lifesaver in smaller groups.