dumb question, once you pick a body type, and/or even pursue enhancements to that type, are you stuck with it for a long time (i.e. MAG)?
No. You can switch body types in character customization. But you also have to redo your loadout, as Lights can only use Pistols, SMGs and Sniper Rifles, Mediums can use Pistols, SMGs, Sniper rifles and Assault Rifles, and Heavies can use all of the above PLUS heavy weapons.
Dude... what i lose in health i make up with the ability to not be hit...
I don't say this as a knock against you, but you're exactly the type of Light user I love to murder. Because you think your mobility will save you. I can't even begin to count how many Light users I've torched because they though they were going to slip & slide away from me. I happen to be damn good at hitting moving targets, and I time my fire not while you're sliding, but were you're slide is going to
stop. Or better still, why waste the ammo? I'll just underslung nade where your slide ends, then fill you with lead while you wonder what the hell just hit you. Contrary to what TruGamer97 thinks, Light is FAR from the best body type. All you get is faster running speed, a longer slide distance and a wall hop. I'll stop every one with a underslung nade...every...single...time. ESPECIALLY with one of my soldiers with both nade upgrades. And then lets not over look the mismatch of a light versus a heavy wielding a Hjammerdiem (my Heavy weapon of choice). Without a damage buff, I'm stopping you could with 2 shots, and with a buff, OHK every time. I'll take being able to hit a grand slam every time rather then a base hit single.