Hey, thanks for taking the time to write up this awesome feedback. I'm a Senior Developer on Last Epoch. Short version, I'm happy to say that our priorities line up very well. Almost every day I work on and talk to other people who are working on performance. We release performance fixes and updates in every patch. This upcoming one will be no exception. We've got more fixes coming down the pipe for the one after that too. Every frame counts and we literally cheer for each one.
Each zone transition's interaction size is set manually and some of them might be a little big. When holding down the mouse button, the game is actually simulating clicks over and over. As soon as you click on an exit, it activates so that when you get close, it makes you leave. This ends up with it feeling like it auto transitions sometimes. It's funny, I haven't heard this feedback in a very long time but this is the 3rd time I've heard it in about a week so I'll go back in there and see if we can make it feel better.
Have you ever played Civilization? We're building a Epochepedia style game guide that will be in game to help explain things to new players who are confused and also detail out specifics for advanced players who want to min/max. (less protections and penetration are the same thing, one just applies as a debuff to enemies and one applies as a buff to you.)
Advanced tooltips and tooltip dps are in the works. Our skill system is extremely modular. Right down to individual behaviors. This lets us quickly build-a-skill on the fly as you're using it so we don't have to save fireball in 100 different combinations. Because this happens at runtime, it's very difficult (not impossible) to have the tooltip reflect exactly what is going to happen. It's on the list for sure.
Pathing has problems, we're on it!
Time rift portal minimap icons changing after completion is a great idea that I don't think we had on our radar yet. It is now.
TLDR: great feedback, we're working on (I think) all of what you mentioned we need.