Those are the same mutants I had trouble with early on. Klaus gave sound advice; place a couple of mines, fire a shot or two and they'll come running every time. For the suicider, focus on crippling his legs first, then you can pick him off at a safe distance.
As for companions, I rocked with Codsworth for quite a while, so I've only had Piper and Cait after that. Cait is starting to annoy me no end, so she is soon gone. If you do the Trinity Tower radio broadcast quest, then you get the chance to have a super mutant as your companion. Try wooing him, Qs! 🙂
As for armor, I FINALLY figured it out. Ballistic weave is where it's AT! total coincidence that I figured this out, but with the armor perk maxed out you can get a simple Trilby hat modded up to like 110 in damage protection. Seems to only work with regular clothes, but then you can further upgrade your overall protection by wearing conventional protection like a chest piece and such on top. Somehow think I got this 'ability' from doing some side quests for Tinker Tom, but not sure.