Scavenger: You may only use or equip items that you find in your travels. You may not purchase anything, ever.
Shouldn't be too tough, right?
You may add that you can't reload to get different equipment while scavenging.
Aha! Good point. Also, on a side note, I've noticed that some chests and barrels seem to have contents that scale by level. I was level 9 or 10 when I happened upon some things in the Salted Coast that were very much nicer than I would have expected for the area.
Yes, in Book I loot scales according to the player level (I found Swordsman's Gloves in a barrel in Aridell late in the game that I'd forgotten to check early in the game once).
In Book II, I believe BW has said that loot will scale more by area difficulty, rewarding a player who'll risk sneaking into a powerful area when they're lower level.