Larian Studios Forums Divinity - Original Sin Divinity - Original Sin - Enhanced Edition NPC Inventory

Been thinking to do a playthrough on Enhanced Edition for the first time. Just a couple of quick questions with regards to NPCs that kinda aggravate me in the classic D:OS

1. How/When do NPCs refresh their inventory?
(Do they still refresh only after you level up?)

2. Do NPC vendors clear their inventory?
(I.e. sold my junk to the NPC and it will disappear from their inventory after refresh. I find it annoying how in the original game the junk i sold stays with the NPC and clutter up their inventory, makes it so hard to browse their stock. I avoid crafting like a plague lol since its so tedious)

3. Do items sold by NPC vendors scale with your level?
(This should probably be a yes just like in the original game)

4. If items sold by NPC vendors scale with level, does that mean they will stop selling low level spell/skill books at some point?
(Another issue that seriously bugged me, i've had a couple of times where i missed low level spell/skill books because i didn't have the gold to stock up on theose books or didn't regularly browse the dozens of NPC vendors for spell/skill books to buy)

Thanks for your answers!!!