I owned 1.4s at one time. Good speaker. Your setup may not be ideal but should sound quite good. If the price is right, go for it.
I have a pair of SMGc's in the corner of a small (11x15 feet) room. The left speaker tweeter (tweeters on the outside) is about 4 inches from the sidewall, the right is maybe 2 feet from the opposite wall. I have acoustic wedge foam along the sidewalls to limit high frequency reflections and absorb some of the back wave. I think the sound is pretty good considering the room size and corner placement. I am also using digital equalization to counteract the small room frequency response (Behringer DEQ2496).
I would agree...although you are sold on the Mags...and granted when properly assembled and with the correct material(vocals,small jazz ensemble,acoustic,etc)they can sound amazing...however...there are plenty of more conventional speakers...that can sound equally compelling....and are easier to implement in a room your size with your limitations...one note: the mg12 is severly bass challenged when playing reggae,hip-hop,techno,etc...the 1.6 is much better in this regard