Honestly, almost all these complaints people have about other people in CoD4 I have never had a problem with.
Depending on the map, spawncampers are pretty easy to kill. But I know, on some maps it gets really frustrating. But that's where outmaneuvering them comes in.
I've never heard of a wall glitch on Overgrown, but that one glitch on Creek is really frustrating.
As for Juggernaut, I have never had a problem killing someone with it. I don't understand why people think it's such an awful perk, because I'm almost always able to kill them just as easily as everyone else, and whenever I use it it has never helped me once.
As for 3x Frag, what's the big deal? So he spammed 3 grenades at you, so what? Chances are, if he hit you with one, he would've hit you even if he didn't have 3Frag.
As for Martyrdom, that should be pretty easy to avoid, except for on Shipment. Honestly, sometimes I think you people just complain about certain perks because a lot of other people complain about them.
And as for Frag/RPG spamming on Wet Work... seriously, man? Seriously? That's an integral part of that map. That's what that map is. It's two sides, high ground on both, and a no-man's-land in the middle. That's exactly what the devs wanted, I think. If you're having trouble with the fragspam on that map, then there's something wrong, because it's usually really easy to dodge. Remember: you're safer when you're moving that when you're not.
Don't take this the wrong way, Chubz. I'm just really sick of people complaining about things that one: can't be changed, and two: can be worked around with a little extra effort.
Remember: if what you're doing doesn't work, do something different.