I upgraded my RAM to 16gb in my MBP and am finally able to run the program (even whilst other programs are open) without any further hangs... Sad I had to go this far to get it to work.

Overall, if people asked my for a recommendation of FTMM, I would have to say steer clear of it! I've paid for two versions FTMM and FTMM2 and am totally unhappy.