Just went through your logs a few times, Finally found the error, "1073741819" to be specific. Is related to a faulty Windows installation.
There are lots of "Lacks WinVerifyTrust" posts in the log pointing to common Windows files. I think that means your physical PC has one or more Windows Updates that have damaged the authenticity certificate database that the OS keeps. Virtualbox uses these certificates to check if the files are not hacked before VB allows the files to influence VB. Since the Windows Updates have damaged the database, VB can't know if the files are good and so won't run.
Another known potential reason is that certain AV software restricts access to specific DLL files necessary for the VM.
The problem is not the virus scanning engine but the habit of virus scanners to map certain DLLs into Windows processes. VirtualBox 4.3.14 has extended hardening features which may conflict with virus scanners. We did several tests but obviously didn't catch every case. The final 4.3.14 release contains more fixes in this regards but I've read in other topics that certain users have still problems
In either case, this has over the years been a continuous problem, experienced by VBox users. Is however neither a fault with VBox, nor Whonix.
Have a nice day,