The rolling mechanism is silly and doesn't fit with the lore or capability of SM. In over 200 novels read I have not read about any marine rolling around on the ground like a clown other than when they have been put on their arse or had to do an emergency dive. It's as ridiculous as people dolphin diving in Battlefield etc.

I recommend instead a fast or heavy block/parry and perhaps different dodges since you want to have your scripted blue or red attacks. 


Ideally I would want you to completely rebuild your armour model to have hitboxes, penetration and values along with weapon damage types for penetration, blast, aoe instead of the combat system in place which is a non armour DPS battery approach. There would be field repair kits and the armour would have actual real heft and substance to not be decimated every few seconds by trash mobs that marines in lore just carve through like chaff. 

Challenge could be offset by having artificer items like rosarius or deflector fields such as the Ultramarine Chaplain has in lore stories. These have a recharging shield value.


Optimal play would be about timing with some grace for imperfection, and not relying on "I-Frames" but maybe at heart this is a console arcade game where those types of button mash aspects are the base of the game. 


I was hoping for a tactical space marine shooter and this isn't that... but I think a number of suggestions here could very well improve it and reflect well with the community expectations.