Regen health and ammo from certain actions

Scrounging around to find ammo crates and health stims isn't fun IMO, they can still exist but being able to regen a flat amount or a percentage would be more fun a bit like how Doom eternal does it but no chainsaw in game YET. Example, base effect that every space marine should have after this amount (5) of light attack kills, or heavy, we get 3% ammo + armor recharged. Make perks that increases or changes how this works.

Being at 30% health at most if not all points of a game and not having a way to top off without acting like a loot goblin is HERACY and you know what we do to heretics. Make it so when not in combat we get an health regen. The this should bring us to 100% if we were at 1% in about 3mins.(or longer to not incentivize not being in combat). But when in combat and have not been hit for this amount of secs (10) you get a massive boost to health regen. This boost should be bring us to full in about 30 secs if not hit. And if we do a perfect dodge we get a flat amount of healing, that increases the more perfect dodges we do in a certain time frame regardless if we were hit or not. Again Make perks that increases or changes how this works. 

Also maybe give some weapons life steal?(Life steal is a mechanic in mobas that gives you a percentage of health based off of damage dealt)

I didn't mention parry but it to should be tied into this somewhere.

This is a buff to us space marines so give enemies a way to block healing in a zone. Or have a new special whos job that is.

This idea plus the to change difficulty scaling to have more enemies should make you want to engage in fights plus wanting to master the skills in game as there's will be a more a tangible result on these.