Unless vector manips are basically perfect, that is going to end very badly for your VR dummy. Not saying they aren't perfect, just saying they might be. More importantly, they have a very defined area of effect, (at least, the one's we're allowed to play with. Frigging plasma projector.) so you'll be launching a lot of extra atoms. Worse, you (probably) can't phase the automanips while they're manipulating, so they have to stay in place.
Also, gravity works harder on the atoms in your feet than in your head, so some of your atoms are going to drift simply because of that. It may be minor, but having your atoms move any real distance in relation to others is probably really bad. Another problem is that there's a lot of atoms just floating around, even in air, and suddenly having a bunch of *new* atoms all with electrical repulsion of their own in their everywhere is probably going to be quite explosive. You would have to either phase into a vacuum, or remove the atoms at your arrival point.
Lastly, those automanips are going to be very big and expensive. Yes, they'll be accelerating particles that are effectively in a vacuum, so there will be no friction, but they're still making a lot of mass go at a high speed. Unless you mean "Fraction of c" like "My car technically moves at a fraction of c!"
PREPOSTEDIT: Actually, isn't 'heat' just atoms vibrating really fast? That would mean the moment you release the electrical bonds, you would scatter off in every direction at already massive speeds. You would have to cool yourself to absolute zero first, and even then I'm not sure if atoms stop vibrating. My knowledge of atomic physics is insufficient to really know.