I've never understood why there is such a stigma behind being an investor while also being licensed. Full disclosure and good record keeping is all it takes. If you are a buyer then act as one and never provide consultation as an agent would. If the conversation steers that way then a choice needs to be made. You either respond by recommending they seek counsel on what you're offering as an investor; Or you stop acting as an investor and become their agent with zero personal interest and seek a separate buyer for them.
If they ask about what you intend to do with the property after they have been put on notice that you are an agent it is their choice if they want to move forward. They also have a choice to do their own due-diligence and uncover what strategies and options they have with their property, including rehabbing and reselling for a profit. They then also have the choice to figure out how to implement that strategy just as we do (raising money, using their own, taking out a loan, etc.) Wanting to sue you sounds more like an emotional reaction to what they felt they should have done but didn't have the commitment to completing. Disclosure stops that emotional reaction in it's tracks.
If you feel safer investing by utilizing a required disclosure statement and release I'd say go for it. Having something in writing is always better than the dealing with the headaches and time lost later.