Ravi,
A couple of suggestions. No subwoofer will ever disperse sound "all over". Because of standing waves and room "nodes", there will always be areas in any room where you will hear exaggerated, greatly boosted bass and other areas (nodes) where deep bass from your sub may be almost or entirely inaudible at certain frequencies. The trick is to locate the sub--and your seating position--somewhere between these two extremes. By the way, it doesn't matter which way the sub driver faces. Just don't jam the port up against a wall (or stuff it with anything).
You know about putting the sub where you sit and crawling around the room until you find a point where the deep bass is smoothest and most even, right? Then you put the sub there.
If that doesn't help, try adjusting the crossover frequencies on the receiver (if possible) or on the sub, or both.
If wall-mounting is out of the question for the M3 surrounds, then at least try them on stands near the side walls, aimed across the room at each other, perhaps forward of your listening area. I wish you could get them up higher--a few feet above your head--but direct-radiating surrounds can be a real pain to place successfully in some rooms. I was never entirely satisified with the direct radiators I had wall-mounted high up in my den in my Toronto home. That's why I never went back to direct-radiating surrounds, because the multipole surrounds I eventually installed proved to be such a huge improvement in envelopment.
To improve the blend of the VP150 with the M22's, try the tip I suggested in The Axiom AudioFile newsletter.
Regards,
