@Robert Jordan  Unfortunately those rules are there for a good reason and help keep those STR markets 'healthy' by making sure residential properties don't have too many people for safety and noise complaints. 

Property current mortgage 72,300 5/1 ARM 5.5 percent opened 2/1/20Refinance: Around total 77,000 cc/fees/prepays payment near 545 30 year fixedCurrent payment with adjusted tax will be about 640 per month on the 5/1 arm So i would save about 100 per month but lose a few years in making up costs........................thoughts?? 

As long as you don't have glaring safety infractions; missing hand rails, broken windows, no CO2 detector etc. you will be fine.

If they can go that high you may be looking at a portfolio loan where it's a Fixed term 5/ ARM I/O and the rate is above 5% with a 1/2/3 year prepayment penalty. 

I've heard 70% is the norm but my realtor suggested 60% LTV to be more risk averse.I'm thinking with 70% LTV it will give me more money to buy more real estate which ultimately provides similar safety as my portfolio grows and accomplishes the same thing as a 60% LTV ?

5 year ARM with a $100k down, which was a loan from my mom.

At the time did a 10-year ARM @ 3.125% thinking we’d sell and move on 5-7 years down the line.

Not sure if you have done it yet: but now while in escrow or under contract would be the best time to go check with building and safety and see if your ADU will be permitted by city.

In two years time, you could have over 50% equity in both investment properties, cash to buy another deal if one came along, and a safety net for emergencies. 

The next thing is building requirements, from fire safety to bathrooms and ADA compliance.