I'm looking into a few different options now: HELOC on other investment properties (though I'm finding rates are 11%-13%), a business loan on another business I own, and negotiating with vendors to take deferred payments. 

Cash offer do carry weight as they can close quicker, don't need appraisals etc, but as an agent that works with buyer and sellers, I've seen it many times where a seller will pick a different offer due to some connection to the buyer (ex military, young married couple just starting etc) They want to know its NOT going to an investor specifically. 

Realize your own experts may provide you guidance that leads to a different decision.In CA the LLC is $800/year. 

In your opinion, does this make a difference if we wanted to sell or refinance on it in the future?

What are the different types of Multi Family properties I can purchase?

So while the rents should be getting $1100-$1200, if you submitted it cash flowing at $1200, but the rents come in "officially" at $900, then that is a HUGE difference in annualized return and likely the source of the leverage drop.

Has 10k of own $ down.My fear of being 2nd lien holder is -being 2nd lien holder.My atty came up with the 70/30 co ownership to protect our unpaid portion.How would you structure this differently? 

As you can see, success in real estate comes in many different shapes and sizes.

How much do different scenarios cost? 

This is a great opportunity to meet potential investors and get a sense of different communities.Remember to be proactive in reaching out, ask questions, and be open to learning from others.