Heroic feats questions

HI!

I can understand Dodge this! because it adds some accuracy and a load of crits, but even with that one and easy mode, my crit is very slowly crawling up. Is it because I use rifles and thus I shoot only a few shots compared to handguns for instance? Does crit only increase in case of a crit, or a hit is enough? (or maybe a glance too?) Is it a fixed amount per instance, or does it depend on the attack ap?

I'm a bit more confused about Fast Runner. Basically, it gives movement AP, no enemy reactions and evasion. It feels very good for a melee character, but beyond evasion, does this somehow benefit a ranged character or is it just subpar compared to Dodge this! for them? And for melee, it has to contest with Juggernaut.

Cult leader feels nice, but it took me ages to understand that it is for the MC too. I feel like it is Very good on a team of 3 or 4, and decent on a team of 2, but maybe team of 2 benefits more from Mastermind? (In return, I feel mastermind worths very little when not solo, even for a team of 2 it is "do everything or you will miss lvl10 and thus you substitute your most valuable first feat for 2 feats later"). Is my feeling right regarding these?

Lastly, Healing Factor feels very good but all the money in the world is not enough to get all implants overclocked if you also have teammates, and Juggernaut feels decent (but it seems to be mostly for tanking, blunt and burst fire weapons), but also juggernaut feels like it benefits from low CON (like the syntethic heart's one upgrade), yet it also benefits from heart, subdermal and spine implant (and squad leader is always beneficial even with solo, considering the upgrades). Which one do you think is more reasonable for Juggernaut, going 30 hp to trigger the better DR (and synthetic heart's upgrade) more often, or going as much CON as you can to get 4-5 implants? Also, what triggers armor skill increase? Is it either-or with evasion, or being shot at increases both?