Zero reason not to: there's no heroes here and conventional weaponry doesn't help against monsters.
I assume monsters can grow stronger with training and time.>OPM
Fuck no, only when threatened by monsters and after that I'd either try to surrender to HA for off-chance they would hire me or fuck off and live in the wilderness where nobody can report me.
Fat, Asobases, Eureka 7.>how would I end
I imagine monsters are immortal so with any luck I'd live for thousands of years until some unfortunate accident or catastrophe claims my life.