Er, wait what? C++ is a superset of C. It includes all the functionality of C
Actually, it doesn't. Examples are designated initializers, compound literals, anonymous structs/unions and variable-length arrays.
You are, however, correct about the fact that the low-level stuff is most of the time just the same and C++ is just as fit to low-level tasks as C.
supposedly you get 80% of X86 speed when it comes to emulation but while having the longer battery life.
Actually, it's rather x86 applications run at about 80% the speed of native MIPS applications.
A shadow can move faster than light. If a wavefront is impacting a linear object, the impact point can move far faster than the propagation speed of the wave.
These are only apparent movements. If I point a laser pointer to a wall, I may say “the dot moves” and everyone will know what I mean, but actually there's nothing moving there, it's only the location where the light from the laser pointer is hitting the wall that's changing.
Obviously I could calculate a velocity anyway and make that velocity greater than the speed of light by choosing the distance between laser pointer and wall big enough, but if it's all about whether you're able to assign a velocity, you may as well calculate the velocity of thoughts: Divide the distance of two places by the time you need to switch between them in your mind. Just look at the sun (or some more distant star to avoid eye injuries) and then at your desk and you're well above light speed.
The ability to define a velocity does not imply that something's moving.
(So, technically, those examples are “faster than light”, though I'd dispute whether something actually “goes faster than light", as the OP phrased it)
Variables don't; constants aren't.