Is it possible to get to atleast the first one without having help from someone?
On a hunter, yes it is possible to solo farm these. I spent a few hours doing this yesterday. It is definitely far easier with another player in there, even if he's a hunter you're splitting chests with.
It's not really worth it to go down to the second level when solo since it isn't possible to farm fast enough to run into the instance cap.
The caster mobs can be easily soloed with LoS gimmicks, just duck behind a pillar/corner for their cast and keep concussive up on them so they don't move toward you much. You can also just stand and shoot since their damage is pretty low. The melee mobs will kill your pet when you've got them down to 50%, and you'll have to kite the rest of the way. The little troggs have like 700hp and should always be zerged down immediately, or else they will daze and wipe you.
All of the pulls but one can be pulled one mob at a time when the two mobs are furthest apart. For that double pull, send your pet in to grab aggro on one mob (caster if one is spawned) while kiting the other back toward the entrance, then drop down the ledge and follow him up and down the length jumping for auto and arcane shots. I was able to reliably get one of the two mobs down before they cornered me on the lower level, but you can still scatter and disengage through him/them to continue kiting (this should make more sense when you're inside). Everything else is just one mob at a time all the way to the end of the escort tunnel and then to the center platform, but you have to be rather careful with unpulled mob aggro and the little running troggs.
BM spec is pretty convenient thanks to the extra threat attached to intimidation, but any spec should work reasonably well. I used a tallstrider for the tanking debuff, but soloing was pretty kiting-intensive so this may not be important.
Is it quicker to just die to zone out?
Definitely. Death is just a jump away, and the spirit healer is right outside the instance now.