Bought them each a car ($4k limit) when they graduated high school (getting ready to buy the last one), they have to pay for maintenance and insurance.

You could sell and 1031 it into the next property but you'd usually have to time the sale of your existing property and the closing of your new property right.I also wouldn't worry about having central air in the property unless that is essentially a requirement for you to remain competitive with the rest of that market.

SB1033 is likely useless for your intent as it allows jurisdictions to Set their own requirements which is exactly what existed prior to SB1033. 

Whenever you are using leverage, you need to have ample slack in the system and sufficient cash reserves (or access to cheap & instant cash) to cover vacancies, capital expenses, unplanned maintenance, and other issues to avoid missing your note payments. 

You won't sell it if you didn't get permits as most municipalities require you to get a CO or the buyers will do an OPRA request and see you didn't pull permits.If you did electrical or plumbing without a permit, the walls will need to be opened up to expose the work.You won't be ready to sell in 3 months.

Maintenance Plan:Create a maintenance schedule to keep the property in good condition.

Mike,Under most Insurance policies for rented dwelling, apartment buildings, etc. that include Business Income or Loss of Rents coverage, it requires a covered loss. 

@Guy GimenezWere you required to make payments?

The main challenge was discovering severe foundation issues late in the process, requiring a quick pivot.

I didn't have a specific clause in the lease about dog poop, but the lease did state that I would charge $100/hr for any maintenance that was due to tenant negligence.