This looks like a basic/common ARPG. Some things are good to keep, others to add/change. Like for example, chat could be on the same spot poe chat is, with transparencies (dunno if this can be done), leveling up icons/stuff could be displayed inside the chat with a message that says ''<name> leveled up to level ''x'' kind of thing.
About stammina orb, I think it could be moved a little to the left, put it on top of the right-bottom corner of the life orb. Make it toggable as you said, when its toggled it turns into ''greyish'' like its not being used. Also, add the run walk stick figure on top of it like you did, but without the red part.
Speed of R/walk could be upped too, with new resolution it can feel like you are going slower. Also, teleports should be capped to the old range (since you could be max range blink).
The icons could be a bit bigger instead of the tiny ones we have. The Red dot on it its also good, this would be better, in fact, than the pop up message icon you just implemented. For the quest one (which is in WIP) could be probably added to the button pannel too.
Gui could be a bit more bright, since its so dark it might as well be black lines.
Shortcuts are okay, I would add a shortcut to equip the gear (only when you have a empty slot in the gear, ex: no boots, find boots, shift right click (or w/e) and it equips.
Overall, game has come a looong way, we all gotta congratulate whist for the hard work and time spent in this. We can't really wait to see it finished.
Edit: Something like this