[So we got another "Mass Kill" mission, can we get an actual Stealth one next?]

You seem to be looking for some really hardcore stealth, and while I agree a bit more actual ninja in a space ninja game wouldn't be a bad thing, I don't see anything as difficult as what you describe being. Instantly failing or being boned for the rest of the mission doesn't feel like it would be fair to newer players.

On a different note, if it does go in, I feel like a hardcore stealth challenge could actually fit in in an interesting place- the mission after you get captured by the zanuka hunter. (Totally not because both that mission and the hunter itself very much need a rework) it would be cool that if you got caught you would actually have to sneak out rather than just charge to your first weapon and mow down all the corpus that are supposed to be stopping you. 

[Tenno Biology Topic "if We Can Slice It, We Can Study It"]

it has been referenced that the tenno are actually infested by the thechnocyte virus (or however you spell it.) we were going to be turned into mindless infested, but going into the void corrupted the virus, but in turn it slightly corrpted us. thevirus gave us raw power, but provented us from living in the the regular dimension. so, we created warframes to let us survive and to harness the raw energy the virus gives us. also as the arbiters have shown, the tenno can speak, us protagonisits just don't need to.