LiFePO4 and LiMn2O4 chemistries aren't magic, although they are less prone to 'rapid disassembly', there is always a possibility. LiCO4 does have advantages though, mainly related to energy density. For something like a car, or a plane, higher energy density in cells means greater efficiency for weight vs. energy potential. Also, it isn't like lithium cobalt is going to explode if you look at it wrong. Nearly all the risk can be prevented by proper cell management, via electronics.

LiFePO4 and LiMn2O4 have the advantage of larger output potential, which for your bike, allows a large amount of power to be put into the electric motor from a small battery. Electric cars/planes get around this by putting lots of cells in parallel, but requires quite a lot of regulation.