Okay, this has still been bugging me...so I just wanted to ask the OP to clarify a few things:
1. Have you tried a battery pull? (didn't see that mentioned above)
2. Is the battery fully-charged? (wait until you get the green charging light instead of the red one)
3. When its "freaking-out", can you do a "adb devices" from the Android SDK? eu1 has reported that the adb daemon should (might) be running even during boot loops? (I don't necessarily know what to do next, but this might be important information to have in order to try something else). If we can communicate via adb, we might be able to push a PB00IMG.zip over to the phone update it that way.
4. What information was communicated to you regarding what state the device was in when you purchased it? (i.e., did you get it really cheap?--implying that it might have been sketchy to begin with?). The HBOOT version and date listed in post #1 indicate that its probably a very early (read "older", first build) Eris. How's the seller's reputation?
5. Just to be clear, a press-and-hold of volume-DOWN and end/power simultaneously still results in a boot-loop? It doesn't stop and prompt for anything?
6. Just to be clear, a press-and-hold of volume-UP and end/power simultaneously (keep pressing and holding the volume-UP for a few seconds even after the screen shows something) results in a triangle with exclaimation point?
7. Does the screen look "normal" (i.e., any defects, scratches, dents on the housing to indicate an impact?). I guess the TOUCH PANEL-fail could indicate a good display but a bad/broken touch input interface.
That's all I got.