I'm mostly on the same wavelength with you on this, but I'll just throw a wild guess that they want us to either invest in defence skills or there will be armour to mitigate some sources of damage (probably excluding lava, since they want that to be quite lethal).
I'll add to your point here: I prefer the old jump stuff too, like you say, especially considering the point invesment. To be fair, currently, with the edge climb the effective height is still pretty decent, but the investment cost for a "decent" skill, is actually 5 skills... Those points could have been spent on crafting recipes and so on. You can always offset height with temporary blocks or permanent ramps/stairs etc...
Hm, maybe if they hit something hard they could get stunned/dazed?
About creature difficulty, in general their health seems fine, considering I've only maxed power and not any weapon mastery, although I admit that Wildstock on Munteen have a very high amount of hp, which would make it quite boring to take on several at the same time - about 40 copper slingbow shots each? (With maxed power and no mastery*)
But at the moment I'm just completely avoiding anything "dangerous"; slopes, cliffs, mobs... since I don't particularly like to lose my durabilities and I can't invest points into reducing that just yet (costs a lot having the durability bonus).