Making claims and pressing them should be an active process, as is dealing with your rivals. 25 years is already a long time for one or two wars. If you can't take the claim you didn't need the claim. Plus, you get buffs to claims on rivals already.

There are only really a few countries you really NEED to improve relations with, and it's not really super micromanagement-heavy. Meanwhile, having a small envoy pool allows for strategic choice(s) for their other actions.

You two, hmm...I disagree, I like the current system well enough;Actually, I think something in the opposite direction would, contrarily, alleviate the issue: make claims go ahead and expire during truces. That way you can start fabricating during truces, at the risk of compounding AE. It's quite unlikely right now that you'd need those claims during truce, and you can only take the provinces with no CB as an ally. And then all your claims expire at once after the truce.