You could always try the Linux iso SBF method. In my experience with the DX, it's pretty much never truly bricked unless you dropped it in a lake or something haha. I've messed my X up in pretty much every way you possibly can and it's still going strong.
Linux solution to your Windows/RSD lite problems
If you were on. 621 and sbf to. 602 it will not work you will have to get the. 621 sbf to unbrick but unless you use Linux root there is no other way to reroot the Droid x due to last ota
There is a .604 (Milestone) iso that you can burn to a DVD and boot from on your computer. It's a custom Linux OS made just to flash an SBF and root the phone.
If you try to flash .602, .605, .596, .340 or any other pre .621 Verizon Droid X build it will not work. You can only flash .621 or the Milestone .604 SBF. The easiest way to do this since you don't have a CD burner would probably be to use sbf_flash on a Mac (I think I remember you saying you had access to a friend's Mac?) or RSDLite on Windows to flash the Milestone build and then just root with whatever method you prefer to root Gingerbread.