I have recorded a lot of flamenco stuff, and believe me it is a challenge.
I was record producer and mixer for Ojos de Brujo, which is a Spanish flamenco band and Grammy awarded. I have recorded some other flamenco players...but let's get to the point..
Listening to the guitar sound itself, it sounds like it has been recorded in a very dead room and sounds too nasal, mostly the first track.
Performance does much of the trick, also, may be the takes are not the good ones.
Also, I think I used tube mics by that time, and you should look for the sweet spots for that particular guitar. One good spot is between the hole and neck end, taking much care in not getting the awful frequencies that come from the hole itself, so be aware, may be face the mic towards the neck a bit.
As well, other good sweet spot comes from the bridge and away, a lot of wood and presence comes from there.
If you intend to choose multiple mics, be careful before recording and find a good placement between the mics and look for the most brilliant sounding combination.
For the above thing, there is this trick... choose two mics and place them until it sounds really muddy and then only then reverse the phase in one of them, hopefully it will cancel the ugly stuff.
I usually record with two microphones, but going for one really, and give all the importance to the main microphone.
I recall recording some stuff in a Blumline array, the downside is you need 2 really good mics of the same model, in a pleasant sounding space.
Don't be afraid of wall reflections, what would be of flamenco without them !
The room was very dead indeed! The prerformance - probably not the best as well, the guy didn't play for a long time and I've manage to convince him to record! In a month or so we will have another go!
The mic's I've chosen were experimental, so now I can chose more carefully,
I could maybe try two u87 in the settings you suggested. The only problem is going to be the room again, all the live rooms in the studio are quite dead so I will really maybe have to use convolution reverb for this.
I really agree that even it's only one instrument there's so much to capture in flamenco guitar!
I'm still going to try properly mix it, and I can't wait to haev another go!