Are ALL the components of a virtual machine self contained in the xxx.vmwarevm file? Other than the fusion app itself that is. So I could just copy that file to a usb stick for safekeeping? Have had a few tragedies with vm's and hoping to avoid it again. I thought that TM would have been sufficient backup protection.
Also is it "safer" to shut down the vm when not in use as opposed to "suspending" it?
With normal file based Virtual Machine created under VMware Fusion the files that comprise the Virtual Machine are placed in a Document Package and generally speaking the Package is self-contained however one should not just blindly assume that the Package is in of and by itself to be the complete package. As an example if the Virtual Machine was created from a Physical Machine with VMware Converter and then migrated to VMware Fusion then in this scenario is more likely than not, and in part due to the lackluster directions provided by VMware, that the converted virtual hard drive will actually reside outside of the target Virtual Machine's Package. In many cases I've seen where on the users Desktop there will be a normal folder containing the virtual hard drive created by VMware Converter and then the Fusion Virtual Machine will be in its default location and its Package will not contain its virtual hard drive. In each case where I've helped a Fusion user via remote access and run across this scenario I moved the virtual hard drive inside the target Virtual Machine's Package and edited the .vmx configuration file to correct the path to the virtual hard drive. Also note that this is not the only case scenario where there can be external references to needed and/or necessary files that are required for the Virtual Machine to function properly so you as the user need to ensure that what you're backing up is all that you need to be backing up.
As to backing up Virtual Machines as far as I'm concerned the only way is that the backup be done while the Virtual Machine is shut down, not suspended, from within the Guest OS and Fusion closed. As an added step and although while not absolutely necessary I have found this to be very beneficial and that is to delete the Applications folder that resides within the target Virtual Machines Package. This folder and the helper applications will be regenerated as necessary as needed.
As to the actual method of backup at that point first and foremost I would never ever under any circumstance whatsoever use Time Machine and I would ensure that there is the appropriate exclusion in Time Machine to keep from backing up any of my Virtual Machines and I would then either make a manual copy of the Virtual Machine Package or utilize scripting or other third-party applications/programs that can be configured to make the appropriate copies under the appropriate conditions.