There obviously is a bug with the "if(user == nero && team == miami) { fail; }" code, it seems to be working backwards. I really need to spend more time on that.
Coaches do just affect attribute development, although your head coach does determine your playbook by his offensive and defensive style. It is possible to get a head coach that has a playbook that is better for your team than others, but it's unlikely to have a significant effect on a per-game basis.
