I can help with question 1 that seems to be stumping people.
Regardless of where you buy, website or Steam, you get the exact same stuff. If you buy it on Steam, you get all the extras that come in the website pack (and if you really want our inferior launcher, you can use that too). If you buy it on the website, you are prompted to connect a Steam account and when you do Last Epoch gets added to your inventory on Steam.
The only difference that I'm aware of pertains to reviews. If you buy it on our website, a Steam review doesn't count towards the positive/negative rating on Steam.
Also, I think that there is a bug with GFN at the moment where steam won't sync loot filters so that's a little annoying.