Tylically junglers aren't trying to make you take any damage; they're trying to kite the buff so they can clear more efficiently. It bugs the hell out of me when I'm trying to kite the buff, only to have my helper stand there and tank damage.
Think about this. If I just stand there while I take my buff, that puts me at a disadvantage. If I stand there instead of going to the edge of the buffs movement range, two big things happen:
- I take more damage. It's just like kiting as an adc. If they stand there, they're going to get killed quicker than if they kite, even if someone is in their face.
- I waste time. If I stand at blue then go to gromp, that's an extra 3-4 seconds. It doesn't seem like much, but take it from someone who mainly plays jungle; those several seconds make a huge difference. Those 3-4 seconds can be the difference of being able to counter-jungle, being in position to countergank, get the jump on scuttle for river vison, etc.
Also, you taking damage and missing cs puts you at a huge disadvantage, so never sacrifice your cs or health for your jungler (unless he ganks you and gets you a kill, he's allowed to take a FEW cs then :p). If a jungler moves from their buff as they take it, they're more than likely just trying to be effecient. If you practice leashing effectively, you won't take any damage. Don't assume otherwise, but if they are making you take damage, GTFO because they aren't worth it.
Edit: I forgot about the first part of the post.
Muting all is actually very beneficial, especially if you're prone to tilt. It'll help keep you from getting emotional about the game and you'll focus more on yourself. You'll learn to make your own calls. You stop following people into suicide plays because you won't care about their flame afterwards. You'll learn to pay attention more. Instead of getting mad at your teammate for not pinging the mia Thresh that ganked your lane and got you killed, you'll be upset at yourself for not paying more attention to the map. It'll promote self focus which will improve your game overall.