If yer bm, consider the 59 bracket, where you have beast w/in - and become unstoppable like your pet. Makes kiting easy when it's up.
You have several ways to slow/stop meleers: frost trap, freezing trap, wingclip, conc shot, that talent that lets your pet stun - if you go hybrid build, scatter shot - and possibly engi'd bombs (or tailored nets). Or netgun.
The main problem is that they get you hamstrung, crip pois'd, frosted or earthbound.
You need to time your, say, stun, so that - well, I'd clip first - if he has a trink, hope he burns it to kill your clip. Re-clip, now stun. Now hit your trink and strafe in a good direction. If you're a dwarf, stone form (or whatever it's called) nixes poisons - and is great for escaping rogues. You can use antivenom made w/ FA.
If rogue, circle strafe, conc shooting as clip is about to go away (make sure he's marked and stung to hurt vanish).
If war he can still intercept - try to stay as far away as you can. You can make a big circle - or you can even just run and let your pet chew on him.
If sham, try to stay out of frost shock range and circlestrafe/kite.
You can also do the following general tactics:
hang back - let the wars and other meleers go forward - come in a few seconds later when most enemy have already made their choices of target - hope you don't get targeted and pick things off from range.
Get increased range talent so you can stay even farther away.
Move around. Don't just plant and autoshoot. A stealthed rogue is slow, if you're moving, you make it generally harder for him to nail u - he may get frustrated and pick another target.
Mark rogues from great range. Druids too.
Mostly learn to kite, learn to escape meleers and kite. GL