Question: I'm just throwing this out there for discussion/answering:

If person A sat in a chair all his life, in a house on earth (let's say 100 years),
and person B flew around in earth's atmosphere at let's say 1000km/h or 1000mph (which ever is easiest to comprehend) for 100 years. 

Would there be a time difference for those people at the end of their life? would person B's clock have ran slower than person A, as person B was traveling at a speed closer to the speed of light, or is this speed too slow to be relevant?

Answer: 
The answer is a qualified yes, depending on your definition of fusion.

If you collect together a mass of iron less than about $1.2M\_{\odot}$ it is possible for that to form a stable configuration, a little smaller than the size of the Earth, supported by electron degeneracy pressure. Such a star would just sit there and cool forever and all that would happen is that the iron would crystallise.

However, if you added more mass and tipped it over about $1.2M\_{\odot}$ then the degenerate electrons have enough energy to begin inverse beta (electron capture) reactions onto iron nuclei. This raises the number of mass units per electron, takes free electrons out of the gas and causes a catastrophic softening of the equation of state. The result would perhaps be some sort of weird supernova explosion, perhaps leaving behind a neutron star remnant (or the whole thing might explosively deflagrate). Many elements heavier than iron could be produced by the r-process in such an explosion.

*If* a neutron star remains, then the neutron star will have a crust above its mostly neutron interior. The crust composition will be determined by minimising its energy density subject to the constraints of charge and baryon conservation. Such calculations routinely show that a density-dependent equilibrium composition is reached that features increasingly neutron-rich nuclei with depth, that can have atomic numbers *much higher than iron* and atomic masses of up to 200 or more.

So, if you count that as fusion (I wouldn't) then yes, you could ultimately produce nuclei that were much heavier than iron.
As I understand it, iron will not be able to fuse with iron no matter how much of it you have gravitationally bound. Instead to fuse iron atoms together requires a supernova.