1. I don't think that'd be necessary; I believe Mozilla will fix it in a day, or two at most (PS: they're currently testing a fix); and

2. I don't know if there's sanity-checking code in Firefox to ignore times in the future.

I tried it and it was set to 0 when I restarted firefox (and the extensions were gone).

I tried essentially the same thing but via about:config. All it did was make it happen immediately on next restart.

Also if it hasn't happened to you yet, make a backup of your profile right now in case it wipes out your addons data as some have reported.