IMHO * Make levelups available only during long rests. It will force a party of warriors to take more long rests. * Make a way to restore all spells without taking a long rest. Mages should use their powerful spells, not just spam cantrips.
Ability to take a long rest from dangerous location is just a time-saver. Who wants to run across a huge empty level just to restore spells?
I like your first suggestion but I don't like the second. The reason wizards don't get all their spells back after short rests is game balance. Without it, there's no reason to bring fighters, rangers, rogues, warlocks, or even clerics or paladins. If wizards can nuke monsters in every encounter, you could just bring four of them and call it a day. Fighters and warlocks renew their abilities every short rest which allows them to compete with spellcasters.
You wouldn't have to run across the map. You could allow long rests anywhere but depending upon the location, you have a high risk of monsters disrupting your rest. Or you could travel to designated long rest areas which are safe. Or add the Leomund's Tiny Hut spell. There's a lot Larian can do.
