I can't really comment on Warrior changes since I don't really use Warrior junglers too much even when Warrior was really strong (although the changes you suggested seem pretty reasonable), but I'll provide my opinions on the other changes you suggested.
While I could be biased from using a lot of **Cinderhulk **junglers myself, I feel like the % bonus health is in a good spot at 25%, and I feel that if any part of the health portion should be nerfed, it should be the base health of the item, not the % bonus health. I feel like the flat health could go as low as 150-200 and the item would be pretty well balanced.
The movement speed bonus on getting hit by an auto attack or single target spell is bad game design for a tank. Tanks have the job to make the enemy team's carries focus them, and this change gives the enemy team's carries strong incentives to not attack them.
Cinderhulk would probably be balanced if it just gave less health than than it currently does, if it need nerfs at all. Which it probably does need.
I'm not sure if Lifesteal solves problems that **Devourer **has. Devourer has some big problems where:
- The jungler has to rush it over other items that may provide bigger powerspikes in the early-mid game
- The jungler is forced to powerfarm the jungle in order to get good results out of Devourer
Any changes to Devourer should be geared towards solving at least one of these two problems so that it can be utilized in the on-hit builds it was designed for.
Also, lifesteal doesn't solve sustain problems for every jungler that takes it because not every jungler buys AD. Some build tank after Devourer, other build AD, and some weird souls build Devourer into AP items (I don't blame them considering how bad Magus is), and lifesteal doesn't help all of their problems. It would probably be better to have a flat heal tacked onto their autos instead if the item got any sort of healing component, but lifesteal isn't really that important.
**Magus **is in a really bad spot, and if I hadn't done any experimenting of my own with AP junglers, I would say that this is a pretty good solution. However, I did some weird experimenting with the jungle in custom games with some of the AP champions that I owned that aren't really meta junglers. I hadn't tested every single AP champion in the entire game (I don't own all of the AP champions in the entire game, nor did I try any AP champions that would either be unable to clear the jungle without the items or that are already known for being meta AP junglers), but what I found would suggest that these changes wouldn't really help every single AP jungler the way we would need it to.
What I found is that junglers either had severe mana problems or had severe health problems. They might have minor problems with the other resource, but it's generally the severe resource problem that holds these junglers back.
Mana sustain on the mage jungle item really helps those with severe mana problems, but it doesn't do anything for those with severe health problems. Magus' CDR and AP might help those with severe health problems, as I didn't actually build it in my experiments, but I didn't really feel it was strong enough to actually be useful for that purpose on most of the junglers I experimented with, and would result in greater mana problems, although to be fair I should have tried it in my experiments anyways to see how it worked.
Mana sustain would, at the very least, be really useful on the item as a whole, but on spell damage might favor champions with lower cooldowns too much more than those with higher cooldowns would be. I'm thinking maybe something more like a burn effect that occurs on dealing spell damage that restores the users mana per tick? That would probably make it's mana restore a lot more equal for a larger variety of champions, especially for those that use burstier, higher-cooldown rotations or that stagger their spell usage a bit, and would overall offer a lot greater amount of mana restoration for a larger variety of champions.