Integrating HT and 2-channel systems

I've now got separate HT/AV and 2-channel systems located back-to-back in a large-ish room (ca. 12 x 32 ft). I'll soon be moving to a substantially smaller space and the "media room" will shrink to 12 x 17 ft, basically what I have cut in half. Something has to give and I'm struggling with how to put it all together. Here's what I've got to work with:

1. HT/AV 5.1 system: 80" TV, Denon AVR-x3600 HT amp, Maggie MMG's*, Maggie MMG C center spkr, Velodyne ULD-12 subwoofer*, Boston acoustics rear spkrs

2. 2-Channel system: Shiit Frey S preamp, DAC and other line level stuff, ML No. 332 amp*.  Everything is connected in balanced mode, no RCA's.  For speakers I've got Maggies IIIa's* and KEF LS-50's to play with in addition to the above.
* FWIW, the old stuff is working perfectly - recapped, factory refurbished, rebuilt etc. I'm not keen on getting new stuff, want to use what I got if at all possible.

As it is, I'm quite happy with both systems. The MG IIIA + ML 332 is quite magical and I don't want to lose that. The AV system is also all really need. But I really don't see the best way to make one system out of 2. At this point my thinking is:

> For 2-chan: Same setup as now - Schiit front end, ML 332, IIIa's.

> For AV:.For front speakers feed ML 332 with AVR-x3600 using unbalanced/RCA inputs?  Obviously other surround speakers just fed by the x3600.
 

Can the ML 332 live with both inputs connected at once?  Obviously I'd have to take great care not to use both at the same time.  Any better suggestions or ideas? Thanks in advance,