also, starting firefox this way just gets me to the basic browser; ex: none of my bookmarks are available even though the .mozilla directory looks pretty complete.
❯ strace -e trace=file -o /tmp/out.out firefox ─╯
ALSA lib pcm_dmix.c:1035:(snd_pcm_dmix_open) unable to open slave
###!!! [Child][RunMessage] Error: Channel closing: too late to send/recv, messages will be lost
not finding anything obvious in the strace output.
A simple thing you could try to do is to create a new profile in Firefox, close and copy all the contents from the old profile folder to the new one.
You didn't mention If you use profile sync daemon (psd) though. If so, this could also play a role in the problem.