Tree of ents is good, but it would require different build, as you wanna use thornstrike which is great feature of this axe, and only way to use it is while morphed as tree. For claring it should be better than deathgaze.
Combat speeds means all speeds, attack, block, hit recovery, just one line of text instead of 3. It is all speeds except movement.
As for MO, you just chose whatever you need at the moment, obviously you don't put all of them at once. There is many alternative gear pieces listed, so there is many combinations, I can't list exactly what to mo, because it depends what exact items are you using, and even at what stage of progression you are. Later you can fit more mo (higher level), and you gain certain stats from charms, which frees up space for different MO.