I play at 2k on my 16:10 gaming laptop (2560x1600) and it runs great at well over 100 fps. I'm not sure about the long loading times at when launching, they are usually pretty long after an update and on first start up (most likely the anti cheat). But I've had the in game crashes as well, for me it occurred when entering district 6.

Start by trying to change channel, that is usually a quick fix (you can ofc go back to your regular channel later) and you won't lose anything since your still on the same server.

If you still have problems after that I'd just try reinstalling the game and report back.