I forgot you had the avr model number in the thread title
Which models of BIC speakers? What sub?
The levels are set by Audyssey to have proper playback not just for surround purposes but in for general use as well; the level is set so that the speakers play at the same level at your seat. You can use any sound mode you want for playback; surround content is generally at a lesser level by design in the recording. Where were levels set for each speaker by Audyssey?
The multi-ch stereo setting is something I don't personally care for, nor many others, altho some prefer it for parties. That is very different from a surround mix's use of the speakers, or something that's been matrixed into surround via Dolby PLIIx or DTS Neo:6 (which I think your avr has IIRC). I either listen in stereo mode (2.1) or matrix it with Dolby/DTS/Audyssey myself (I have a 4520 running with 9.4 speaker setup and have some Audyssey branded matrix modes, which is different than the Audyssey initial setup).
Some like to turn Audyssey off for music, I use it personally in most cases. You have two primary eq curves with Audyssey; Audyssey (for movies particularly, rolls the highest frequencies off) or Audyssey Flat (sometimes called for music in some Audyssey avrs, keeps the high frequencies). Does your unit also have Bypass L/R mode? Some like Dynamic EQ more, some less. It's all a matter of finding what you like of course in the end....
The wattage ratings in the advertising materials are sometimes only a 1ch driven rating, often 2ch driven. Yours looks to be rated 95W/ch 1ch driven (at 8ohm 20hz-20khz .08%THD). Your avr won't put 95W out all channels driven simultaneously at that same rating spec, but will put out a bit more power at a higher distortion level, how much would depend on the power supply capabilities supplying juice to all 7 amps at the same time/level (which is not usually needed in surround modes) and what distortion spec. Bench test on the X2000 I couldn't find, but you might look for a bench test done on a model with a similar rating. I'd guess your avr puts out more in the neighborhood of 50-60w/ch all channels driven simultaneously at that full spectrum/low distortion spec. Try this article
http://www.audioholics.com/audio-amplifier/amplifier-power-ratings