If you have the money, i would do that plus add a metal z channel going opposite direction of the joists ( screwed on top of the existing plaster ) and then add another layer of drywall. the Z channel leaves a space that helps in sound transmission. the problem is the sound is transmitted through the existing floor joists too, so just the insulation will not do it because the joists are still against the ceiling. this is something similar, but in this picture they used clips in combination to hold off hat channel from the existing ceiling which will lower your ceiling about another inch. 

Owning property as an LLC is usually to shield you but since most crowdfunding deals are already LLC you are already covered unless of course you're trying to add more layers of obscurity so more difficult to trace back to you for whatever reason ;).

If your not savy with complicated multi layered entity structuring, than don't try to do business like you are, and K.I.S.S.

For example for a roof you could need new decking or not, are they going to strip the roof or put a new 3rd layer? 

It’s vital to keep it fun and interesting.

My team and I are curious about building from the ground up you seem like you have some vital information and expertise on the topic

I've been talking about it for a good while now, but never initiated to start gathering vital information until now.

Two layers of carpet with one glued solid to the floor. 

Guessing you're desirous to turn your Pittsburg dirt into profits, I think you're on the right track though will suggest strongly that you yourself or someone very knowledgable that you can trust and manage babysits the process down to keys in hand, as I assure you, dealing with contractors and all entities along the developer's path takes an entirely whole new layer of skin and nerve.

A third party will force an additional layer of accountability and precision vs. one person doing it themselves.