please help, what are these crashes

Yes, it is is a possible cause for that crash that the system has exhausted its memory address space.

Ok, I can dig that. The only thing that still doesn't fit is is the amount of RAM both Reaper and OSX are saying is being used (by Reaper). Is it possible part of the RAM being used by Reaper is not being considered as part of the Reaper RAM usage in the meters. Maybe certain plugins or other "processes" are using RAM but it's being considered part of the "wired" (osx system memory usage i believe) so hence I'm execeeding 4gb, but the system isn't reporting that accurately?

well I started running a smaller project in 32bit, with Kontakt and Reaktor bridged. It seems Kontakt is somehow the source, as the project crashes pretty consistantly, with the same report as before, and the bridges' report pointing to Kontakt. Here is the report attached, along with the bridge crash report.