He says this description makes it sound like the Assessor's Map is used as a description which is illegal and won't transfer ownership.

Your primary lender will generally not like having a downpayment being a loan, so you need to be careful about how it is structured and named.Typically, equity investments come with a fixed ownership stake 35/65, 50/50... 

How I would find out who has ownership of the property? 

Net value uses the assessed value from purchase and sale, figuring the difference, with consideration of any miscellaneous contributions over the course of ownership.

I am glad I did this, as it let me live through some of the costs of home ownership, which are similar to rentals: HVAC replacement, water heater replacement, kitchen and bath remodels, etc at my own house before buying a rental that needed these things and not being able to estimate the costs.  

100% of 10 units....more ownership, more control on future income.

On a long term monthly bases renting is less expensive than home ownership.

Deeds to burial sites, certain transfers of ownership in real estate companies and farms and property passed by testate or intestate succession are also exempt from the tax."

But, at 35 I started my first flip, and some 20 something flips later, we saved enough to buy into a 72 unit campus property with a partner (we have the minority part of the LLC), and we also have multiple buy and hold properties; one house, four 4 plexes, and ownership 50/50 in a 5 plex and 8 plex with our son and daughter in law.

You pay transfer tax only when you are transferring property (changing ownership).