Will you guys please STOP complaining about how easy the game is on later levels? Then just don't use smithing/enchanting! The game will get much more threatening, I can assure you.
If we have to not play the game in order to enjoy it, something is wrong. I'm 50+ on master, but I'm nerfing so that I only use dragonscale smithing (maxed) - no alchemy or enchanting.
I recently did that Missing In Action quest, and everyone topeside was super easy. Even without hit bonuses I kept one shotting every single NPC up there and thought to myself "WTF is this? This is waaaay too easy on Master.". I think the mechanics is so that those guys are scaled from the first time I visited the place, but without activating the quest. When I entered the dungeon, things upped a bit in toughness, and due to being stupid I even managed to get killed once

This leaves me with a couple of conclusions:
1) Level locking should not occur by first visit to a new place, but instead occur on first fight in a new place. Exploring without entering combat and fighting everything I see is "how I play", and I now have to nerf myself to not enter dungeons at all until I get a quest for it.
2) With higher difficulties the lower end should scale higher as we progress through levels. The early game was very difficult, and I loved it - forced me to think. At higher levels (at least without exploiting features) high level enemies still pose a good challenge which I can't ignore (ancient dragons are tough as hell), but the lower end ones could be scaled higher. Not to the point where I don't feel I have any progress anymore, but at least enough so that I still have to put up a fight to win.
The first one requires quite a bit of recoding, which probably won't happen. The second one can probably be changed with mods, and could be included as default.
Lastly, up the importance of the now neglected skills and perks. Now I can open every master lock in the game with two or three picks, but I haven't spent a single perk into lockpicking. And I'm an archer/worrier like build.
The game would be "annoyingly perfect" if all skills had perks in them that you felt you really needed but couldn't get all of. If you go for multiple crafting skills, make sure the neglect of others are really felt.
Maybe classes should be brought back, with limits put in even in the custom class where you cannot pick "easy to skill up skills" that conflicts one another? In other RPGs they have tons of these "arbitrary rules" with intention of breaking down power gaming, despite having a role master in flesh and blood with thinking capabilities.
Another big worry is how ridiculously fast I reached 50+, without really doing anything useful in the game at all. And now that I've finally begun playing it, it gives me no sense of progress at all because I use skills that are already max'ed out.
As much as I love the idea about use skill to level up, this is the downside of it. Compare to FONV whose mechanics didn't let me level up indefinitely by skill usage/grinding at all, but instead you had to "play the game content" in order to be rewarded. Progress is divided throughout the game, instead of all at once then complete stop. I enjoyed every build I had, and I didn't have to nerf anything. I felt really good at high levels, yet I couldn't rush through anything (hardcoe mode of course).
Focused skilling is rewarded too much in this game apparently. Even if they should obviously feel stronger than jack-of-all-trades builds, we don't get penalized much at all for not doing it.
Maybe adaptive evaluation (more effective on higher levels) is the solution? Punish us more for the traits we don't have. I wouldn't be the one to program it though

Still, it's too late for this game (sadly). Maybe food for thought for the next one, although I don't expect it to be...
Also, the game needs to get out of this "need to max out" idea. Let it be harder to reach 50 skill than 100 skill, but have all perks available at 50. 100 should be so ridiculously hard to reach no players would ever get there. More cross referenced perk requirements, like i.e. the Sneak perk "No armor penalty" (?) you'd also need to have certain skill levels in light armor (not heavy armor, as it doesn't make sense) in order to get it.