I had a rogue player that completed an entire campaign ending at level 12 and still never knew how many damage dice to roll when doing a sneak attack. I don't play with them anymore.
Long rest taking a week. That's fine. I do that.
An action to get a level of exhaustion to get a long rest makes no damn sense. Exhaustion to long rest. Think about the logic there.
I play 5e and just use the original BECMI War Machine rules as-is. I have Colville's book and ordered the other, but haven't used it. It seems lame by comparison. The BECMI rules can be used almost as-is.
This is why BECMI is the best edition. It went to level 36 and nobody that played that edition wondered what the point was of higher levels. There was plenty of stuff to do.
"Officially, balance between classes assumes 6 to 8 encounter per long rest.
At the same time, there is roughly 15 encounters until reaching the next level."
Both of these statements are insanely false in any game I run.