1.) MCACC may show the wiring or polarity wrong with dipole speakers. Proceed running MCACC and everything will be fine.
2.) Speaker distance is based to the speed of sound waves hitting the mic. Subwoofer distance is usually off the most. This is not a problem due to MCACC adjusting for opitmal listening at the sweet spot/s.
3.) MCACC goes to -12 so readings of minus 10 are ok. Most Klipsch users will have speaker levels set in the negative numbers. Only with RF 82II or higher/equivalent may level settings be a problem. There are mic attenuators that can be used in these special cases.
4.) X/O settings are based the the weakest speakers frequency response. Ideally set the X/O at least 3 db higher than the weakest speaker frequency response. approx. 10 above that frequency response is a good round number to shoot for. I use a X/O of 100 and do not fee I am missing and bass since below this point things are redirected to the sub. Since I have 4 klipsch tower speakers I have tried lower X/O and did not feel that it enhanced my listening experience.
5.) MCACC dose a better job in room correction that most other programs. MCACC does not EQ below 63 hz. MCACC can be adjusted whereas, Audyssey can't. Audyssey does use 8 filters for the subwoofer. which is better, depends.
6.) Sending lower frequencies to the subwoofer is better because most towers cannot reproduce those frequencies as effortless as most sub. For a speaker to do as good a job, as a good sub, it would have to match the volume size of the sub, match the piston throw of the sub driver and have has large a woofer. Two 8 in woofers can't not match one good 12 in woofer. Most low frequencies do not add the presence effect of higher frequencies and are not as important in the overall listening experience in my opinion. Therefore the EQ below 63 Hz is not that big of an issue for me.
Off loading low frequencies to the sub allows the other speakers to produce the frequencies that they do best. These are general principals and not brick and mortar. Following these principals has generally lead to a good listening experience for me.
Klipsch RF 7 based HT 7.4, Pioneer SC 35, Acurus Five 200 amp, Chase SS 18.2(2), VS 18.1(2), Samsung BDP F 7500, Asus/My Book Live HPC 4 TB
Yaquin VK 2100 amp, McIntosh XR 5 speakers, Samsung BDP F 7500