i'm a big fan of the 900 over the 1100 exactly because of the hard-button, wand-style layout. To answer your questions:
1. I use my 900 in a separate room about 30-40 feet from the blasters and it controls my kit w/o a problem. That is through a typical drywall though. I've read of issues where it there's a problem getting a signal through thicker/concrete walls.

2. True. The 900 set up will need to be done from scratch and may not be migrated from your H-One setup.

3. I bought some splitters and cable from my friendly neighborhood radio shack and run 2 mini blasters and 2 direct in cables from my main blaster to control 4 devices in cabinet with the main blaster on top of the shelf to controls the tv outside the cabinet.

After using both the 1100 and the 900 I prefer the 900 for ease of use.
Hope that helps.