Oh come on... you should've waited... It's Christmas...

Now, onto some comments.
1. It's VERY difficult to play it at that tempo, you know that, right? It's not an easy piece by any account.
2. About articulations and slurs... hmmm... It's rather tricky, so you have a point that you couldn't decide on what to do. Perhaps it's best of you left it as is.
For me personally I think that there's a lack of legato slurs... If the tempo was slower, I would've filled each page with slurs (every beat, or every bar, or every phrase or other), but since it's so fast it seems almost irrelevant to do something like that.
3. Dynamics: You want a whole prelude at
mp|? It seems unfair to any kind of music 'sculpting' on could do. There's so many ups and downs and there is a sort of a repetition that you could take advantage of.
4. music and harmony wise I think that it works very much. Some bars are unexpected which makes it even more interesting. Overall it's short and never gets away from home, like you were scared to leave further than 5 feet, but as a short example of a prelude (that IS complete, I don't mind that it's short...), I think it simply works very well...
Thanks for posting, thanks for sharing and for the PM and very well done.
Merry Christmas also (it's already Christmas here in Greece)