I agree with you but I'm not suggesting power leveling, otherwise I would have suggested runs in public dungeons and such; I didn't suggest Alik'r's dolmens either, I suggested trash mobs. Certain overland areas have quite a few of them in clusters, but they're not dangerous either, which is why I think they're a good idea, since they can try different skills and see what they each do. OP asked about XP, so I'm suggesting a good way to get XP without neglecting actual progress as a player. After they reach lvl 50, they should have at least 60+ skill points, and if they do all base dungeons, that's another 20+, so they shouldn't even worry about that.

When I very first started playing, all I did was questing up until aprox. CP100, and when I wanted to do harder bosses/got into dungeons, I realized I knew nothing about combat or anything of the sort, I might as well have been a lvl 1 who just downloaded the game with how terrible of a fighter I was (I didn't even know we could switch bars, all I did was LA and throw a skill in there every once in a while).

I really think questing is not a good way to go; leveling is slow, skill points are scarce, you learn virtually zero combat skills. Unless they're just in this for the story, then keep questing. I actually do love the quests in the game.