You *MUST* use the RUU to restore the old version of the Radio. Unless someone has figured out how to S-OFF this phone, that our only way (RUU) to "downgrade" the Radio...
Then, after you RUU restore, you *MUST NOT* allow the OTA upgrade to install (that is what upgrades the Radio & in my case, causes bootlooping with custom kernels)...
I think it is the the order I am flashing the files now. What you have said, I have down perfectly. When I stumbled across this forum, you guys confirmed my suspicion. I used the RUU and I now have radio 1.00.00.0521_2. I am going to try flashing them in a different order or try a different kernel now.

However, I did find another link to this RUU by googling just the name of the file... I haven't any MD5 so I'm not sure if it's good to go but it looks like it.. bloated as all hell at 331.9 MB.
