That could be easy, just use normal rolling.
Only, while sprinting.
So if you roll while sprinting, you gain invulnerability while rolling.
It can also be faster :3

Shift run, holding D you'd move slowly to the right, hold D and jump, you roll left.

I recall seeing that and I disagree with the suggestion; you don't need to compare 2 games, just use WF. Between Warframe's entire lineup (and RPG system) there's considerable difference in speed. Something like Frost or Rhino that's comparable to an SM is 25-30% slower than Loki or Mirage, that's of course without mods or powers which go much higher than the raw frame's base speed.

Take away all the wall running, power slides, verticle running, the run/sprint speed is an interesting proxy for Orks/SMs and Eldar.

I'd like them to be able to jump off walls into a backflip or have the option to double-jump while vaulting. Steven pretty much said that they'd be able to climb low walls and vertical terrain, these would just give some tactical edge and borrow from the current Assault class maneuver (pushing off walls) or be a second animation applied to the default vault (double-jump).

I don't think Banshees should roll. They should have the mechanic, but I think it would look much better if the actual animation was them dashing to the side, but remaining on their feet and in 'sprint mode'. If they rolled to the side they would lose their forward momentum and footing and have to start running from a near stationary position, any competent warrior would rather stay on their feet if they have the agility required to do it, which I'm sure Banshee's do.

I think LSM/CSM should be able to do it too but they would lose their momentum and have to start sprinting again from stationary, this way they would have a method of dodging large balls of plasma and other large projectiles, but it wouldn't be viable for dodging small arms fire so they would just have to take the hits on their armour.

Slow start up to sprint for heavier armed opponents. I like it. It means that Marines and others that size need to really think about engaging, because when you do, you more than likely won't be able to disengage from your opponents with ease, especially if they are more mobile than you.

Being nimble and light on their feet is something the less physical races rely heavily on. Marines are still fast, but they are still encased in really bulky armour.

I'm really interested and hope they put in refractor fields I think they were called. The visual distortion field that blurs the user so it's hard to get an accurate shot on them as they charge at you with power swords or other Eldar weapons of death. Having a cooldown period would fit well for that piece of gear.

An interesting point and well substantiated.

I think the answer is that we skin Cupcake and wear his flesh as a sports coat.

I think this is the safest option tbh. It'd be fairly easy to implement into EC, and would fix most of the issues highlighted in this post.