Sure, it is improbable that you can swap out knowledge willy nilly, but it isn't intellectually honest to say it's impossible unless you can prove it. the default position should be that is is possible. Until it is proven or disproven, it is an unknown.
No, because the sensible thing is to assume that things work like in our world until shown otherwise. I assume bears are dangerous. I assume cabbages are edible food. I assume that the guy running down the road in my direction swinging a big pointy thing and screaming is in fact a dangerous bandit or thief, the pointy thing is a sword, and he is looking to kill me for my stuff. I assume that as I move higher into the mountains, the air gets colder and there will be snow. I assume that when I see a river flowing, it is flowing downhill and not up. I assume that if I jump off the top of a tower, it will hurt or kill me. I assume that if I stay underwater too long, I will drown.
I see people shooting flames from their fingers in the game and accept that with no problem, because it is admittedly magic (although it retains its own rules) and it is a non-mundane thing anyway. If I see water flowing uphill, I don't think "wow, my assumptions about water were apparently mistaken in Nirn" I think "wow, somebody really should have done more playtesting."
Similarly, if there is a way to swap old knowledge for new without taking the time to learn the new, I don't assume that things work differently in Nirn, I assume that the developers are catering to laziness on the part of a small minority of players, who want to level
one character and then be able to completely recreate that character on a whim.
If you don't like the way a character is, start a new one. I'm not far from finishing with my first character, and I'm gonna start a new one eventually that will be completely different. I cannot imagine going through the absurdity of reshaping my character like clay into a totally different character with different abilities - but keeping the same level.