Joe, that room looks very nice. You've done a great job.
Anyone that can do LF sweeps and produce a proper graph as you've done can certainly operate a
BFD. You really don't need to use the
REW software to set up a few filters on a BFD (parametric equalizer). The method you're using will suffice.
The REW software simply makes it incredibly quick and accurate, which allows changes and observing the result in a second. To do an LF sweep and produce the hand drawn chart you've provided wouldn't be considered immediate feedback - but still effective.
The change that's obviously required for your room (that you are already taking care of) is that reflective floor. Yikes, that must provide a heck of an echo. Impulse response would be interesting. The carpet will really help there.
The dimensions of your room provide first order axial mode resonances at 22.5Hz, 35.3Hz and 70.5Hz. The peak at ~35Hz bears this out. That peak is in an area that will produce predominant bass levels that creates somewhat of a 'one note bass' sound. It would be nice to reduce that peak at 35Hz if possible. A BFD would do it easily.
The BFD simply installs in line between your receiver/processor and subwoofer. You manually set a cut filter at 35Hz of a desired dB setting and a bandwidth at a desired width and then redo your manual LF response test and see if you've tamed the beast. It ain't too difficult...
brucek