@Shiloh Lundahl Above is purely a price and income story, just data.

I just move them around or get the Kwik Set smart  rekeyable locks.keypads are more expensive, more prone to break and the tenant may call you when they can't get in because the batteries died.

The area the property is located is not listedThis is a pure cashflow play as the value of the 3 MH and the land probably does not come close to $69,000. 

They take a 9v battery as opposed to 3 AAA’s like Weiser.

As soon as you look at something that is purely commercial, the down payment requirements jump up to 25-35% pretty quickly. 

During those inspections check the fire extinguisher and change the smoke detector and carbon monoxide batteries (Unless they are those 10 year batteries then just test).Personally I would rather have them and have them documented to be working at proper intervals than not have them and experience a loss of life or full loss of property.

Because the story I heard (albeit he did preface with the fact that it was a predatory loan) was that the parents made the payments on time but still ended up needing to sell it purely because the lender asked them to.

Buy the fuel and/or batteries through the business account.

I am trying to determine if there is any regulations, state or local that governs fire extinguishers in terms of type, how many, and location.I know there are city building codes on fire alarms, smoke alarms, hard wired or battery which is dependent on when the property was built as well as whether it's a SFR or multi-family dwelling.However I couldn't find anything on fire extinguishers. 

Since these are sole member LLCs they are pass throughs directly to my tax returns, and don't file their own returns, so my accountant does not charge for them.As mentioned, from a pure risk-mitigation perspective, having each property in its own LLC is probably your best bet.