We'd certainly like to fix any bug resulting in access violations and UR exiting unexpectedly. The problems you've been reporting do seem to be related to having many tabs open. We don't normally keep more than two or three tabs open at once, but we've been running with 12 tabs for the last few days and haven't encountered these problems, but we'll keep trying.
As far as data loss, you should never lose anything but unsaved changes to the current tab (and using a shorter auto-save delay at 'Tools | Options | Editor | Auto-save changes every x minutes' can reduce the unsaved changes). Most users do find UR to be very stable (typically, we only hear from those having trouble). I do apologize for the problem you're encountering and hope that we can eventually isolate and resolve it.
As far as data privacy, any files you send are kept strictly confidential and the contents are not examined beyond what is needed to reproduce problems. We can also look into providing a debugging build to run on your system; please contact us at
support@kinook.com if you'd like to pursue that.