Ishamael, I can help you with Gahz'ranka and Jindo.
The big hydra is a considerable walkover. The only thing to wantch is your own positioning and his aggroresets.
Basically position your pet with it's back to the cliff or something similarly solid (where it is to it's back when Gahz is engaged). MD him when he arrives, then run to the statue with the nose and stand directly below it. This is to prevent getting thrown in the air where it can hurt when you land. An alternative is to fight him in the water where it doesn't hurt to fly around. The water option provides the freedom to move away if he is tanked too close (big hitbox), while the former gives the advantage of less time spent in the air.
He drops aggro now and then and be ready to use FD for that, so go 'gentle' at all times, you don't want to have to FD before an aggroreset. Deterrence is of course a great cooldown for him when FD is resisted or you have messed up.

Even if you do mess up a lot he doesn't hit all that hard and there is plenty time between resets for you to use bandages and your pet should regain aggro pretty fast.
Tank 'n spank...
Jindo the Hexxer, now he is an unusual boss in that here your pet is not to your advantage. Expect to have to melee him down. Kill all the trash in his courtyard first though. Engage him with ranged abilities with no pet out, then melee him. His strikes are not terribly hard and with Dragonhawk up you should dodge a good deal of his attacks. When he uses the mindcontrol totem you stand a very good chance of getting healed to full, and if not you should have the health to survive until the next totem. In essence he is pretty easy, if quite lengthy and horribly boring. Using traps for extra DPS is adviced.
Ayamiss the Hunter: Ouch! I'm not certain she can be soloed. I would think a Ferocity pet would be the best bet for when she sacrifices you (need to kill that worm fast). But with her hitting your pet as it kills the worm, it could turn nasty if Mend Pet is just running off (remember Ferocity).
Buru, if I doubt that Ayamiss is not really soloable I would consider Buru a Holy Grail of solo. Technically possible if you are the most efficent controler of your pet and have a multicapacity on the order of an octopussy.