Ignoring the tax implications would be ignoring my only question.

Has anyone used social media to find scouters?

You can certainly ask if the are interested in selling, but any implication that you are offering some cure to the FC issue can get you in trouble.The best way to determine value is for you to be aware of that market, past sales of similar properties that will likely be used as comps in a sale.

You will withhold the same amounts of Social Security and Medicare as an employer.

Advertising an option, needs to be disclosed in the ad, you don't want to rely on that "equitable interest" as you do not have the bundle of rights of ownership to say "house for sale" which by practice and implication is an offer of providing good title.

Use social media - Facebook and LinkedIn especially - to let people know about your new business.

I would re-negotiate if you are still interested and let him know you understand the implications in not reporting total purchase price has on you.

In my opinion they are a social and economic night mare.

There are different tax and financing implications depending on the structure and renting vs not for your brother. 

I do have the option to start receiving my social security next year.