Several points.All answers and explanations much appreiated
For subwoofers, always use the standard Vertical graph axis of (45dB - 105dB) and the Horizontal graph axis of (15Hz - 200Hz) using the Graph Limits button in the top right corner of REW.
For full range, use the standard Vertical graph axis of (45dB - 105dB) and the Horizontal graph axis of (15Hz - upper limits you desire), i.e. 2.5KHZ in your case.
For full range, enable smoothing to eliminate the comb filtering. Use a 1/3 octave smoothing.
For waterfalls, use the same vertical and horizontal axis as used for frequency response graphs (as explained above), with a Time of 300msec-600msec and leave the Window at 300msec.
Set the X=1, Y=50, Z=150.
Be sure to set the mode to LOG rather than LIN using the Freq Axis button in the top right corner of REW.
No, if you want RTA/Spectrum, select the Spectrum tab. Take a look at this post on how to set it up.Is the 'filter adjust' readout the equivelant of an RTA/spectrum