Now I can boot into Windows but only 1 monitor is active. I have 2 HP 24" displays connected but only 1 works and (right-click desktop>screen resolution) 1600x1200 is the highest res listed, although the native resolution on these monitors is 1920x1200. Is this the limit of the MS driver? It's strange (to me) that I don't see Display Adapter or VGA, nothing related to Display Devices listed in Device Manager.
The generic VGA driver for windows only uses standard(ish) VESA modes. Widescreen resolutions like 1920x1200 aren't among them (but a big 4:3 resolution such as 1920x1440 likely is). Windows is giving you the best resolution available between what your monitor's EDID lists and what the driver can provide, which is 1600x1200.
Likewise, you only have a single monitor because the generic VGA driver doesn't have any dual-head support either. There isn't any "standard" way to do that, I wouldn't think, certainly nothing VESA was involved with. It's probably completely manufacturer specific and it comes from a very different era than the VESA modes did. If you had two physically separate adapters you could use both displays, but the generic driver is very, very "basic" as you yourself put it.
This is intentional. It is only there to provide you a display should all else fail, it's not really meant for anything else. I suspect support for the higher resolution optional-but-still-somewhat-unofficially-standard VESA modes
was just provided because lower resolutions like 640x480 et al can break UIs and/or be generally unreadable. That's really the only difference (other than 32-bit color support), graphically, between what you are doing now and actually running in safe-mode.