Q#1 - Is the 30" recommended height for the BRX's (as front L/R) purely to line up the tweeter in line with ear level. Or is there a different reason? As my MLP is while sitting on the floor thus my ear level is MUCH lower.
Q#2 - How much space do they need from the walls (side and back)?

Hi cgott42, the recommended speaker stand height of 30" for the BRXs would place their tweeter at ear level (in most applications). If your ear level is lower than "normal", feel free to use shorter speaker stands. Happy Listening!