My property manager is insisting he only needs one person to sign it given he only needs one SSN on the W9 for tax reporting purposes.

Where to start with guidance and then drilling down what my personal potential is?

Send him a letter, emphasize that you are personally yourself the end-buyer, include proof of funds, include something attesting to you being financeable (unless your proof of funds is for the full cash purchase price).If he owns 20 local businesses, good chance he's in at least one chamber of commerce, and if he's not, he 100% knows people that are, who will spill the beans and offer to do an intro if you mention you're interested in buying a gas station over a beer or a meal (there's probably like 3 people in that city that fit this description, why not get introduced to all 3?)

If I personally understand the skin in the game first hand, I would think this will help me become a better manager of my team on it in the future right? 

Also, while I've read some horror stories about assessed value increases, our personal portfolio came out relatively unscathed during this recent batch of tax bills.

We hardly ever meet our tenants in person.

If rent is not paid we follow up personally.

I plan to hand write the letter to keep it personable and local.

On a separate note, if my personal home and all my business is in the state of Michigan at this point, would there be any benefit to designing the business as a series outline or simply a parent/child LLC set up where the parent LLC would be created in a more tax advantaged state such as TX, WY, NV etc?

I personally have invested in a couple syndications in the last 3 years and none have been completed yet.