How's the equipment?

You can take a decent exterior shot with a cell phone if you have a little but of talent, but interior shots require specialised equipment. 

If you are not equipped to, then do something else...or get equipped to.SDIRA's have solutions to every problem he mentioned. 

I've got a couple of quotes and the equipment goes from $150 to $400 depending on model.

Is he going to bring all of his tools and equipment with him?

More info is needed about your equipment and what your tank temp is, and include what house heating you have. there's lots of answers like raising the temp and adding a mixing valve if you don't have one, but I need to know more.

I personally would leave the current mower with the new tenants (and to have verbiage in the lease that holds you harmless for any equipment malfunction etc.). 

There's too much gray area with lease options and lots of pending litigation, I don't think I'm equipped to answer this.

There are no dollars assigned to new HVAC equipment or a water heater. 

After the Purchase Agreement signed, there is 5-7 day for general inspection and usually 3-5 days for any other inspections, recommended by the home inspector.Besides, some inspections require special equipment installed and removed.