First part :
-Removing the ambush in that TS makes it more fair, you don't have to react to 20 mobs teleporting on your face (and possibly instant-killing you)
-That venom was actually a big glitchy and ticked 1k/2s or so instead of 250/action, no big loss here
-I don't remember this one at all
-Kukukeen was overly tanky (about twice the base HP or so, something like that, can't exactly remember), so it makes it a more decent fight
-Wasn't neccessary to remove that debuff, the mob was a caster and it summoned casters, and the closest thing able to crit would be a cog boing
-For the last two changes : THANK YOU. These things were pure anti-mage. It took me way too long to kill 8 for the quest due to them refusing to take damages even with 4 burns stacked and fairy booster, my final would hit as low as 900 depending on its mood
Overall : healthy changes, with the extra HP they have, it still is slightly harder than vanilla, but more fair to the player, which is the most important part.
Second part :
Nothing of value was lost. Their average HP remains above vanilla, but even -10% is a big change that improves fights quite a lot. Especially that cursed tree (seriously it refused to die, hiting 4k/auto, took me about 3 minutes being AFK on its face, and it is mandatory to kill)
Overall : again, good difficulty adjustments where they were actually needed. I'll try again that 5.1 TS and hopefully I won't pop a blood vessel screaming at my monitor when the avengers ganked me.
Thanks for listening to feedback (for once, this is extremely rare, almost every server out there ignore feedbacks).