I don't have a property manager on them since I have 10% down, they take care of the place as though it's their own.

CAREFUL ..

Investment Info:Single-family residence buy & hold investment.

I have been fully consumed in all the BP podcasts and it pushed me to turn my primary residence in Wilmington into a long term rental. 

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?

The concept here is to get to the point where your tenants pay for your housing expenses, which should give you some excess income to save and invest.These initial steps could get you to a point where you have a few doors and maybe even have your tenants covering your own housing expenses.Think carefully about selling, it seems counter-productive if you want to be an investor.

Does anyone know if you can use a DSCR loan to build a DADU on you SFH primary residence property?

It is low risk because you can use a low money down primary residence loan, you are right there to deal with hiccups as you learn to manage an STR, and if it doesn't work you can just switch it to MTR or LTR pretty easily.

AND you must maintain adequate reserves to take care of the disasters that may happen.So my advice- build your equity.Most of my clients fall into the first group above.

If you are self managing you might take a rapport approach with the most responsible resident or one you have best relationship with.