I want happy campers in my network - you've helped reiterate any deal can be good at the right purchase price.Huh, well, that is a kudos on your level of research or you've got some serious luck on your side because as chance has it I have experience working both with organizations similar to what you described and in leasing by the room. 

There's a lot of other things to consider here but I'll go through your list and make some suggestions based on 10 years of investing across various asset classes - single family, multifamily, industrial, storage, retail, office, etc. and I've had experience with section 8 housing, BRRRR, flips, etc.Purchasing rental properties?

Any advice or shared experience would be great.

In order to get there it would be good if you could keep feeding cashflow proceeds back into acquisitions, on top of your continued W2.Speaking from experience, you can manage probably 30-50 units yourself nights and weekends before you really need to hire someone.

Sounds like for now the idea of eventually selling the branded account is a no-go, but there still remains pros/cons on each option and I'd love to hear what others have considered or their experience in adding more STRs/boutique hotel type properties to their portfolios.

Rent control in the bay area can be extreme as many areas have rent control in excess of the state mandated rent controlIn general experience RE investors are not choosing to add a single ADU in single family zoned areas.  

Having no experience is risky.

Most of the lenders I work with (provided you have experience and a credit score over 660) would do up to 85% of the purchase price and up to 100% of the rehab costs, provided this doesn't exceed 75% of the ARV.As for the idea of selling the land, great idea.

You’ve gained valuable experience from your first duplex and are now approaching real estate with a strategic mindset

What you want is an agent with experience who knows how to negotiate, watch your back, navigate difficult situations, understand contracts and law, provides an objective cross-check, etc.