Once renovations were complete, we had 5 separate units to rent.

In this approach does it really matter if the Operating and Holding LLCs are completely separate given the protections a Series LLC provides?

The insurance companies have rules on the number of rentals that can be directly covered under a PUP (for Allstate it's 4), so if you have enough properties you might have to use separate insurers.

I'm just very straight forward and I deal with mostly men in regards to subcontracting and really don't see any reason for me to separate myself from them.

Since ADU rules were liberalized by Seattle in 2019 (one attached + one detached allowed on any single-family lot, no owner-occupancy requirement, no restriction against separate sale). a number of spec builders in Seattle have been building what may look like a townhouse triplex but is legally a single family primary homes plus two ADUs, one attached and one detached. 

You should open a separate bank account for all your rental activities.

Separated meter for the ADU, the garden unit and the main house.

@John Majoris Playlist Beta subscription accounts are separate from BiggerPockets accounts and is not included in the Pro Membership. 

Follow-up campaigns using CRM tools and email marketing software can be valuable for managing and communicating with your buyers as the list grows to see where the real engagement is then separate the quality of buyers into buckets. 

Those sales may happen off market between you two, or may have creative terms, but really you're negotiating two separate sale both of which only happen if you both like the terms.