I would post obligatory link of someone calculating expected number of universes on top of ours based on planks distance and something else, but I can't find it.
There are negative temperatures, but I wouldn't characterize them as being "lower than zero kelvin". It would be more accurate to say that negative temperatures are "higher than $\infty$ kelvin".
Value that reaches maximum possible energy goes negative?
Maximum temperature, not maximum energy. Negative temperatures are even higher energies.
The real issue here is that T is a dumb unit -- 1/T makes a lot more sense, and when you look at it that way, the trend is just "higher energies have lower 1/T" and passing through zero is entirely unremarkable.
Instead have this simulation argument here: http://www.simulation-argument.com/