Electric/gas are a completely different story and would require some local knowledge about utility usage/rates as that would vary greatly from location to location.You should find out if it has separate meters before doing anything else.  

If he wants to do something that inappropriate he would simply hide it from you, if you made him sign something. 

I'm sure if you have the utilities in your name and you show usage, who could argue against that?

Then utility usage becomes the tenant's responsibility.

At least out west the FBI and the US AG's office has been very active the last few years prosecuting "collusion" on the courthouse steps.

(Catering, lunch rooms, WiFi, etc.)How do you charge for space, availability and usage?

Check with your CPA or Tax specialist on the rules regarding vacation home usage for personal use.There are tons of Snowbird parks and properties in Florida/Texas/Arizona and other southern locations where you can afford to buy without breaking the bank.  

There are also other considerations - roof loading, wind shear, switching & wiring decay - that can eat into your profit pretty heavily.That said, you have two major things in your favor: density of usage and a favorable climate.

Bay area especially suffers from the low inventory created by high regulation (both by limit land usage and high cost on permit)- I do agree as long as tech stock performs well, the housing market should be solid after seeing how my colleagues behave- I am curious whether the high income tax and cost in CA can tweak the population trend.

with fair usage from the tenant I would go about 3-4 for paint and carpet cleaning.