This is a lender and personal question.Lenders look at your monthly Debt-to-Income Ratio.

@Shiloh LundahlTheoretically assuming properties were identical in every sense yes because I don’t need cash flow and would rather have the extra $100k in equity.Now $600/mo could get you another $100k mortgage to get you another property that could potentially also cash flow but for me personally I am in equity play mode now income mode - just my personal choice but nothing wrong with the other scenario

Recommendation letters would be fine as well, but personally, I think talking to them over the phone is more ideal as it's easier to get answers and just a better understanding of the tenant. 

Since the DADU is on the same property as my primary residence, can I place the DADU in an LLC, separate from my primary residence, to protect my personal assets from liability?

If you can't keep control of your personal finances, you are highly unlikely to succeed in real estate investing.

My worry with leaving the local agency is the personal attention that guests receive when they call.

In a better market you might be able to use those things to get a better deal on commercial insurance but in the current market there won't be flexibility.On personal policies/1-4 unit rental dwelling policies there won't be any flexibility whatsoever unless it's something the company already has built into their guidelines/pricing.

Then visit the lender website and see if the have an REO section or try to find a person's name.

These are all private so someone had to include them, and then that person can pursue you for failure to comply.

Basic recommendations- Deed of Trust-Personal Guarantee-Promissory note-JV agreement (to protect the lender from violating usury laws)-clear late fee schedule, cure period agreement-cross collateral if the subject property doesn't safely cover you with enough equity