I think there should be a "level scaling-slider" like the difficulty slider in Morrowind. Lowest there would be for example: "Every item and NPC is +-10 levels( either 10-0 levels lower or higher than your level)" or you could choose "Every item and NPC is fixed level".
If they implemented this correctly with values that you could choose yourself, i think the problem would be solved. I would personally choose the "No level scaling" option.
But i think there should be an interesting mechanic introduced in a S.T.A.L.K.E.R. (FPS with RPG elements in horribly mutated Chernobyl) overhaul called "Oblivion Lost" in that mod (along with other improvements) the NPC:s would "level up" when time went on. So if a lowly, novice level bandit would manage to survive for example 10 in-game days without dying (enemy factions and monster can kill it anytime), it could get some better equipment and advance to Expert level bandit. When the bandit eventually died it would spawn back, but in level novice level again.
This feature was really interesting in my opinion since it would make the game a bit more challenging and realistic. However i would only implement this on human enemy NPC:s like bandits and marauders, in the wilderness. (because it would be quite annoying in dungeons since they could be like level 40 when they were originally level 10.) The animals could maybe level up too, but at least the human ones.
-Emp-