If you purchase the property as tenants in common, then either of you can sell or pass-on your interest independent of the other - unless you have an operation/shareholder/partner agreement which spells out that the other party has first opportunity to purchase the holding of the other should they want to sell.You are headed in the correct direction that you should have an operating/partnership agreement between you and your sister ... it's worth spending a few hundred with an attorney to have one drawn-up and executed.

All of the people that emailed me, including him, all spoke in the same manner and all had the exact same poor grammar and spelling.

. - this is a very competitive space, so I would just spell out exactly what you are looking to accomplish and bounce it off of 3 intermediaries and see where they land. 

As long as what you want is spelled out in your contract and signed by both buyer and seller then all should be good. 

Typically the seller will not care too much where the money is coming from on a cash purchase - only if a conventional lender is involved.You should have someone draw up and an agreement for you both spelling out the terms and rules.  

@Chris Frieberg No, the answer is spelled out in Florida statutes: http://www.leg.state.fl.us/Statutes/index.cfm?

It should all be spelled out in the association's documents.

Evan,just because you are cash strapped right now does not make you a bad investment to lenders. get all your financial information together, and put it on paper with your total net worth. have all the information for the properties you want to buy all spelled out, rents, dept income, make sure to show that they will pay for themselves, see if you can get past rental history. bring that all along with you when you go to talk to the lender, they will be happy you are all prepared.

Every single detail should be spelled out in these type of deal.

Then, within the LLC you spell out ownership interest of parties.