I am going to upgrade my home office listening experience. My primary goal is great audio while working from my desk. I have a pair of Sonus Faber Electa speakers that I'll be using in a near field listening position. My main source will be a Mac Mini that has has several thousand CDs that I ripped using a lossless format. I may or may not add a subwoofer at some point but right now I'm going with just the 2 speakers. I had thought about getting a DAC and an amp to do all this, but the RR2150 seems like a better solution. OK, so here are some of my questions:

1) First does the USB input support UAC2? I would think so but I don't see it listed anywhere.
2) I'll be placing the unit on a shelf, how much space does it need above the unit for proper cooling?
3) I intend to bi-amp my SF speakers using the A+B outputs, these are 8 ohm speakers so I should be all right. But it does bring hop some setup questions.
4) If I run the tweeters off the A side, can I use the Bass management setting at its max (100Hz) to minimize the low freq. signal being sent to the tweeter? And if I understand it correctly I'd still get full signal to the B side which would be driving my mid/bass speaker. Is this valid? Am I missing something?
5) I typically don't use tone controls, but I am curious do the tone controls only apply to the A speakers (like bass management) or do the effect both A+B speakers? I would guess both, but its not clear since the Bass Management only apples to the A side.
6) Also, there is a "Speaker Eq." setting that I'm not sure of its function. Assuming that it applies to both A+B speakers, if I have the Bass Management set to 100 to trim the low end going to my tweeters, could I then use the "Speaker Eq." to boost the low end on the B side that drives my mid/bass speaker?
7) At some point if I decide to add a sub (probably the M8), my thought would be to use the crossover on the sub instead of the RR2150 bass management. Keeping the configuration as described above the same, I would take the output of the B side to the sub's "Speaker Inputs" use its crossover circuits and then take the "Speaker Outputs" of the M8 back to the mid/bass side of my speakers. I can't think of any issues with doing this, can you?
8) This is a M8 question relative to my previous question. I understand that the "Crossover Frequency" adjustment provides a low pass filter to the amp that drives the sub, but does it also provide a high pass filter to the "Speaker Outputs"?
9) One last question, again not really related to the RR2150, I'm currently using iTunes for my player (yea, I know it's kind of lame, but it was easy and free!). Does anybody have any recommendations for a better player. My main goal is best sound quality, but it does need to be user friendly, i.e. I'm not interested in some bit nibbler's command line interface software. Oh yea, it has to run on a Mac Mini running OSx 10.9.5.

Thank You in advance to any and all who respond.

Regards,
Mark