ToME: the Tales of Maj'Eyal

First off, tome is awesome! This should totally be the future of roguelikes.

When I go into the dungeon, out, and back in, it keeps the layout but there are new items all over and new enemy's around. Is this normal?

Yes it is normal after a certain amount of game time elapses. But items inside an unopened vault are saved.

You sure? I thought opened vaults were also "holy" ground for items.

I'd also like to add that artifacts don't decay.

If you clear out a vault new junk can be generated inside, so I thought it might lose some of the ones left behind.

One one problem is that I can instantly see all the items that are regenerated in the rooms. Does anyone know how long it takes for a floor to regenerate? It seems too fast. Just leaving the floor, regenerating, and entering it = a new set of things to fight.

Or even leaving first level of the dungeon walking to the town, selling stuff, coming back it's all regenerated

It has to do with in-game time. If you go down a dungeon and then come back up new stuff is generated on the floor on the way up.