Difficulty curve needs to be adjusted. The difficulty settings increase linearly with HP and damage while your character's power level increase exponentially due to weapon/armor material/quality/enchantment strength all stacking multiplicatively (This is also the reason playing a mage in vanilla Skyrim feels bad, because of the lack of exponential scaling as spells are mostly flat damage)

Bigger towns with more verticality would also be nice, Whiterun was like 12 buildings in total, but that's more of a technical issue.

The combat system is kinda clunky and could benefit for more in depth mechanics. Playing on highest difficulties as a melee often means you're constantly going forward, hitting the enemy and then backpedaling to dodge his attack or blocking with a shield.

Magic is not a good option for a build, as the other comment says, so that could be expanded because some spells are really cool. It's still playable but you definitely feel less powerful than other builds.

Without mods, combat sucks. It largely boils down to spamming heal and the attack button.

To add to this, the vampire lord and werewolf add some much needed extra depth to the combat, however I do wish they fleshed them out a bit more. Their respective skill trees are very shallow. The werewolf besides being able to transform into one, has little effect on the gameplay beyond just that, while the vampire lord, comes with so many negative effects that it's almost not even worth it.

The quests also suck for the most part. Besides what you have already mentioned in regards to RP, characters have boring and shallow personalities and you're often expected to care about people who you barely interact with (Skjor from the companions is a great example of this). The quests are also often exceedingly predictable. It's such a huge step down from Oblivion.

The random encounters are great and all, but when you keep running into the same ones over and over, it's a bit immersion breaking. I would have preferred a system similar to RDR2 where each encounter doesn't repeat itself and they are all unique.

Magic (more specifically, destruction magic) has so much wasted potential in Skyrim. It scales absolutely horrendously, making it nigh impossible to make a good magic focused build.

I think larger settlements would be nice, and most of the guild questlines could definitely be improved. I think the option to toggle quest directions/icons would be nice, so both types of players could have what they prefer

Ability to pick up quests or map markers just by hanging around taverns and inns and passively listening to conversations around you.

I don't think that the engine supports spline-based curved surfaces, where the polygon count dynamically increases as one gets closer to something rather than relying on pre-generated LOD geometry. It would have bee nice to do that as a way to leverage newer computers -- could have added more polygons to the game.

I enjoy a bunch of Skyrim mods that use the Papyrus scripting engine. I wish that there was a better system for diagnosing performance, and I wish that there was a better system for leveraging multiple cores and only triggering based on set conditions. I haven't dug through the API myself, but as far as I can tell, a number of CPU-intensive Papyrus scripts do so because they're having to frequently scan surrounding area for a given set of conditions; my guess is that it would be more-efficient to have the engine permit scripts to register being triggered only when certain conditions occur, and for any scanning that must occur to occur in parallel.

I'd also have liked a better system for diagnosing mod problems, try to make them more-approachable. Like, try to tell me some likely causes of a CTD. I recall an extension manager for the classic Macintosh, Conflict Catcher, which would, if a bug came up, try disabling half of one's extensions, ask one to see if the problem came up again, if so enable/disable half of the not-ruled out extensions and so forth until one had identified the problematic extension; it was also capable of finding problems resulting from the interaction of two extensions. Would be nice to have in games that support mods.

I'd have liked a mechanism to reduce startup time for very large mod collections. Skyrim starts up a lot more-slowly with a lot of mods. Maybe cache some sort of preprocessing, like a list of the assets and that they're valid, or have support for deferred background loading for things that aren't immediately-required. Like, have a priority queue of initializations to do, and only bump an initialization to the front of the queue if it's required.

On wanting paper maps, I don't think I agree -- I remember playing the Dungeons and Dragons gold box games and having to manually map dungeons out on paper. I didn't find the manual cartography aspect of it all that fun. That being said, I could changes to RPGs that reduced available information. Say...starting with a "fog of war" covering the initial map -- I mean, you're supposed to be new to the area. You don't know the waypoints. Why would you know the landscape? And instead of a system that places precise waypoint markers on the map, maybe one that just gives some sort of more-vague directions, with approximate distance and direction. Maybe if you find yourself in an unknown area, the computer starts a new map that is only linked to another map when you see something you recognize. I think that this is generally a problem in RPGs, though, so I can't beat Skyrim in particular up too much about it.

I preferred the combat in Fallout 4 to Skyrim. The ranged combat is either with crossbows/bows, which is okay, but not quite the same experience, and the magical combat just didn't come off as all that exciting to me. Some of that is just the nature of the fantasy/tech world -- no guns in Skyrim -- though Tiny Tina's Wonderlands shoveled fantasy-themed guns into a world without too much trouble. Also, I think that it'd be interesting to see more-sophisticated melee tactics from intelligent opponents. If one considers historical battles, having a line or some other way to leverage numbers was used, rather than having people willing to go charging one at a time at the other side. Ranged attackers don't really leverage cover effectively, either.

The intro in Skyrim was quite good...the first few times you played the game. Yeah, I know that there are mods to skip it, but I do think that the game should have provided a way to skip it, just create a character in the more-conventional fashion.

While the game works fine on Linux, getting mods fully running was a headache for me. I think that some of that would be alleviated if the game just had a first-class mod manager built in.

A number of dungeons just...don't really make a lot of sense. Why the simple puzzle locks in Bleak Falls Barrow, say? This isn't so much Skyrim's fault as it is many RPGs in the swords-and-sorcery tradition; I think many games in the genre have lots of game elements that just aren't that plausible.