@Joe@Joe Edmonds I think the lock idea is fine but if I couldn't trust them to have access to the breaker panel I probably would't rent them the house. 

I understand the emotional strains of running a business.

I've certainly thought about the strain that it could put on our friendship.

Everything else is a strain. 

And the tub is bizarre, although I wouldnt worry about an access panel.  I

However, the selling process would be less straining and completed sooner.If anyone has dealt with any situation similar to this, your experience would be greatly appreciated.

In a perfect world this would work out but you know the minute the tenant has a grievance/gripe and wants you to buy something or repair something that’s unreasonable In cost there is going to be strain and resentment.

@Calvin Lipscomb No, needless to say it put a serious strain on the relationship.

If your panel is a 150 or 200 amp version and has lots of unused slots for breakers, you've most probably got enough capacity for the new kiln. 

Have you found that the growth (particularly medical and arts), including population growth, has placed strain on the cities infrastructure, or not necessarily?