We're not a sponsor or capital raiser, we don't get a cut of any of the money invested. 

I consulted a lawyer and a few other investors to see if there was anything else to try to do, but they all told me the only way I was likely to see my money was if they went to try to buy a house one day they would need to pay off my "Lien" before proceeding. 

Using Hard Money 10% down 100% rehab loan to finance the deal.

some ideas:- yes you could put more money down upfront, even though it's not ideal.- Look for off-market deals that are much cheaper,  using hard money and then refinancing with a rental loan.- Find properties where the owner will finance most of it, so you only need a smaller loan with the higher interest for the down payment.- Take over a property where you can continue the seller’s lower interest payments.- Another thought to give why would you want to do a rental at all, I mean those terms are horrible. why not buy something else with a better return on invest?

We have also decided that family always comes first, money is just money and if something happens to our partnership or management style we will sell the building.

It depends on the hard money lender.

You can however use a hard money loan!

We're here to help if you ever need hard money lending!

How would you suggest I use this money to generate the maximum amount of monthly cashflow? 

The risk/reward ratio does not seem worth it, there are other less risky places to park your money with better returns at the moment.Also, as someone pointed out, you didn’t account for property management.