New to Udio, some questions

So i have played around for some days now. I wonder:

1 - I feel like Udio almost never take into account my tags.

If i use tags like:
Oboe, polyphonetic, medieval
Most of the time i get something that not have oboe in it, is not polyphonetic and not medieval. I think it has created oboe in 1 of 99 tries. I crank prompt strength up high, it does not seem to matter.

2 - If i like one part of one creation, and another part in another creation, can i somehow make both parts appear in one creation? If not in Udio, can i manually cut and paste offline, the reupload the song to Udio and continue from there with extend? Or does Udio has som metadata in the songs that disappear when i manual edit in .wav offline?

3 - I want to change out the vocalist for another vocalist in one specific part in my song, but keep everything else (instrument, melody, lyrics) the same, can i do that? Maybe using stem in some way?