>>11 This is how I picture it in a sort of two-dimensional heat map. The red represents the 'dent', high density, the particle (in this case, let's say electron). The blue represents the lowest possible energy state. The green is intermediate density. The green tail is the (in this case) kinetic energy actually pulling the particle ahead. The spiraling arms are meant to illustrate the spin in the dent/density.
A positron (anti-electron) would be the same thing with an opposite spin. The spin is very important as it is what give the density coherence like the winding of a rope. With out the winding, the rope would unravel, and without the spin, the high density would dissipate into lower density. Matter-Anti-matter Annihilation would be two densities of perfectly opposite spins coming into contact, which would cause the spins to cancel each other, resulting in the matter of both 'unraveling' into energy.
As such, you see, there really isn't negative energy, merely particles with opposite spin.
As for time travel, I consider it an impossibility. You could ,if you were a God or something like that, move everything back to the exact place it was in the past, but that wouldn't really be the past, now would it; It would be a future state indistinguishable from the past.
I don't know about portals, though.
>>19Perhaps the friend's step-father just re-paints it a lot.
As for the Blue->Black->Blue, dark blue automotive paint can easily be mistaken for black.