FCP 10.2, I've never had problems like I'm having now

Please forgive the rather terse tone of this message, but I've been wrestling with this for several days with no change in how easily and often FCP crashes.

Okay, I removed it, restarted, reinstalled it and so far it has: Crashed on start-up, several more times, Crashed while updating a library, Crashed right after launching without me doing anything, Crashed while creating a new project, Crashed while importing footage, Crashed while scrolling through footage, Crashed when creating a new project, Crashed when that footage was added to the project, Crashed while scrolling through the timeline, Crashed while looking at the info tab for the footage, then crashing four more times on relaunch. Font Book says all questionable fonts have been deactivated. Q Master was removed with all remaining vestiges of FCP 7.

I have work, clients and competition. Help me fix this.

Or even better, a return to the days of "It just works."

OS X 10.10.3 (14D136)

Mac Pro (Late 2013)

3 GHz 8-Core Intel Xeon E5

32 GB 1866 MHz DDR3 ECC

AMD FirePro D700 6144 MB