Skyrim is generic good vs evil rubbish from 1995 back when Wheel of Time was in. Witcher is real life wrapped in a fantasy skin. Full of nasty people doing nasty kinky things and you in the middle of it. I'd take men beating the stuffing out of their wives, relentless poverty, random hangings, vicious racism and drunken singing trolls over generic Lvl 50 character killing three dragons in 2min after a few hours of playing.
The biggest issue I have with III isn't the combat, which is fine, its the stupid consolized UI and inventory. While isn't alchemy organized by type? Why don't letters and maps have their own section? Why is inventory full screen? Why is everything full screen and built for a TV? Why do I feel like shooting myself every time I scroll through 536 crafting diagrams and you can ONLY scroll? Where is the organization? Why can't you chuck diagram's you've crafted or are crap compared to your armour in another section?
For the quests, the best option is you being one level higher. If you are Level 5, forget any quests above Level 8. Level 8 is barely doable. If you just follow the main quest (really not a good idea) you'll likely level up as the devs intended, but if you mix a whole of pile of side quests and contracts in you'll be more rounded. You get no experience if you are 3 or more higher levels than the monster you are killing (I think). And on combat, you don't need to pick one skill to lead to another skill, you just need points. And you can only have 12 active skills and 4 mutagens active at one time - match the mutagen colour to the skill colours for a fat old boost. You really want a couple in combat, plus the delusion skill, plus the potion one to increase duration plus some of the other skills that only have one point.
That map of Velen has Novigrad and Oxenfurt, around 70+ question marks and at least one or two side quests/contracts in more than a dozen villages not counting random events or treasure quests. Then there is Skellige and Kaer Morhen either. Beat that Skyrim. I only have done one part of a quest that could be considered a fetch quest and that was leading a goat (don't ask).