He charged us $85 at one time to change batteries in 4 smoke detectors.

The classic example of legit "unforeseen" is that your mom who lives 3 states away comes down with terminal brain cancer and you want to be near her for her final months.

And charge $500 for early termination fee's with no mention of recourse on lack/no-performance on their part?

If they give you any grief, then you'll probably have to terminate their lease as well. 

After one of his friends assaulted another tenant with brass knuckles, I was able to terminate his lease agreement early. :) Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

After one of his friends assaulted another tenant with brass knuckles, I was able to terminate his lease agreement early. :) Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

I was set up with the utility companies to automatically put utilities back into my name during a voluntary termination since I'd never had a tenant stop utilities unless the tenant was moving. 

The tenant wants to break the lease early (6 months before lease termination).

If I understand correctly, the tenant has not yet moved out, has properly noticed lease termination at the end of April, and has not paid April's rent.

The property is in Illinois, so we are aware we should give at least 30 days written notice to terminate the lease.