1. I found the battery on amazon.com
2. I can sync over IRDA and the other bluettooth. This is not an offer to teach how. http://en.wikipedia.org/wiki/Palm_OS
3. As to upgrading wifi. No.
4. "every time I push the sync button, the TX performs a soft reset. Not even a pause"

Item 4 is the killer. I got myself into that situation and resolving it seems to be beyond "owners" and "users." I write Palm applications so I can avoid the call to support since I know to do the hard reset, setup a new user and migrate into the new user name. Again it's far too much for me to offer one on one support for this beyond sharing how I got my PDA back.

Remember I write Palm applications so I own about a dozen models of the Palm units. I'm writing to share and not as a replacement for your support lines.

5. The SD card issue. Could be contact failures. Rare but most often seen on many year old units where people use them a lot. However since the machine can't hotsync that could be a sign that software issues are afoot. You would do the hard reset (bye bye what's installed) to test.
Bob