I am that other beta tester and can scarcely recall ever having problems with BFD2 32 bit or 64 bit in sonar.
Definitely move your samples to another drive, obviously make sure it's a fast drive 7200 rpm and not green or blue.
Internal would be best too. You might find that alone will fix your problem, if not then try the 16 bit rather than 24 bit
You really won't hear any difference.
As far as the jbridge option goes, (not that you'll need it) it is integrated into sonar now so you should be able to go to the plug in manager, choose the VST you want to use jbridge with, click properties and you'd see a check box to use jbridge.
It should then open all your existing projects that use BFD2 with jbridge so you shouldn't need to create separate projects.
Steve