Rope climbing and roof hopping was a bigger part of Daggerfall than later games, so such actions would be more a return to form than a radically new gameplay mechanic for TES.
Thank goodness someone said it! And not just
climbing walls. There were spells to improve your jumping. And landing safely after a huge jump. And you not only had levitate spells, but
flying spells. It was not just designed for, but
expected in dungeon exploration. And to some minimal extent, that remained in Morrowind. But then you get to the two-dimensional Oblivion where not even flying creatures could actually
fly and the whole concept of vertical movement was just not there. Heck, a big scene in storyline denied access to simply by making the gameplay so vertically challenged. In Daggerfall people would have been all over it by accident purely out of curiosity! So yes, number 3 there really was a deviation made specifically in TES IV: Oblivion and is normally
not a limitation in TES gameplay. I can't even begin to imagine the hell Bethesda will face if they don't bring vertical movement back in TES V. Not only because it was so important to be there before TES IV, but because where TES had been so ahead of the times in the past, now modern games practically take the concept for granted. You have to be crazy to create an immersive 3D world now and
not think of wall crawling and dramatic leaping.