FileVault triggered "panic" freezes in Yosemite

Question

Turning on FileVault seems to have triggered succession of problems.
MBA 11 inch (late 2010).  1.4 GHz Intel Core 2 Duo. 2 GB 1067 MHz DDR3. NVIDIA GeForce 320M 256 MB.
Upgrade from Mountain Lion to Mavericks by clean installation at Mac Store in 2014. Subsequent successful update to Yosemite 10.10 (14A389) (Kernel Darwin 14.0.0) online with no problems on 17 October 2014 and in subsequent daily use.  However, this week on 4 November 2014 turned on FileVault for first time ever ... at which point kernel panic problems started for first time upon restart necessary as part of process of turning on FileVault.
Various panic reports so far, including:
4 November: panic(cpu 1 caller 0xffffff801de1e80a): Kernel trap at 0xffffff801ddd8d15, type 14=page fault, registers:
4 November: panic(cpu 0 caller 0xffffff800ce1e80a): Kernel trap at 0xffffff800cdd8d15, type 14=page fault, registers:
6 November: panic(cpu 0 caller 0xffffff801321e80a): Kernel trap at 0xffffff7f943985d8, type 14=page fault, registers:
7 November: panic(cpu 0 caller 0xffffff801ee1e80a): Kernel trap at 0xffffff801edd8d15, type 13=general protection, registers:
Workaround :  After multiple restarts and "panic" screen freezes, the panic reports have (so far) eventually resolved themselves each time by simple (if time-consuming) method of turning completely off and then turning on again repeatedly. Not great.
On positive side, after a couple of days the Macintosh HD is encrypted (as is now the remote TimeMachine backup disc). The "panic" freezes continue to occur intermittently, seemingly at restart from hibernation or start-up.
This repeated freezing has never happened before on this computer in 4 years until now. Do I just to have live with this?

Answer 1

11 days later and continuing to get CPU panics on restart, particularly if am restarting with power lead plugged in after battery has drained to zero.
Seems best never to shut down/restart if at all possible, otherwise am in CPU panic loop for ages.
Turning to PC alternative at times when I need a reliable connection for work - MBA is worse than Windows now for crashes, and even less support.
Perhaps I need to a day or so unencrypting everything (including Time Machine) and try and go back somehow to the time when it all simply worked - all in all a nuisance and an utter waste of time and energy.