Greetings guys,
here are some quick thoughts me and a mate had after ~ 120h of Space Marine 2, playing mostly co-op and missions
(we are not the PvP type players, still played it a bit but the co-op is where its at for us).

- at least for the highest difficulty give us some boundaries we have to overcome, the idea with the range penalty for armor reset on
  executions was a new refreshing mechanic and forces people to adapt to overcome this challenge (just expand the range and the mechanic is a great idea).

  -> if people dont like the mechanic they can play the missions on other difficulties but for the most challenging difficulty available in the game
      those little mechanics add great spice to the missions

      -> keep making unlockable skins behind achievements / challenges (like the helmet you get when you get all missions on lethal)
          ,keep adding these kind of achieveable skins e.g. "dont get hit from the hive tyrant once in the 2nd mission bossfight" or something like this.

This gives us refreshing challenges while still playing the same missions and waiting for new ones to appear.

- for the motivation to grind, expand the class levels to 30/35/40 whatever and add new perks for the skill tree.

- add new weapons and weapon tears (energy axe for example) -/- new weapon tier (orange?)

- new classes (Techmarine, Apothecarius, Psyker) ?

UI - quality of life 

for me personally, I am still missing the team mates armor plate indicator. Let us see the current armor plates they have below the HP-Bar. 

This leads to better teamplay because you then give the execute to the player who needs it the most in scrappy situations.

Just a few quick thoughts coming up, thanks for reading.

I think the idea itself was good but the range itself was way to short. As you say e.g. assault class takes a huge hit, thats why they should play around some decent range thats not to restrictive but also needs your teammates to cooperate and I agree without your friends it might be even more difficult and if you try it with randoms evenmore but then it is kinda rewarding to then unlock new skins in my opinion.

To have a challenge at the highest possible difficulty and maybe even needing +10 attempts just to finish 1 mission on lethal thats what drives to play the missions if you have nothing other to unlock but wanna keep playing the game (but that might only be me).

But I see your point aswell.