Congratulations on getting some interest! Ill avoid giving any warnings and just say that even though I'm a recent member here, I have followed your Posts and admire your spirit. Well done!!
I have my first, and ONLY, dollar taped to my wall. But I also have a short, simple, contract giving me 4% of all sales. BTW, that 4% is not "after profit", it's an up-front 4%.
My advantage though, is that I know where the producer lives and can track him down if I have to send some thugs over to collect

....The internet, and Hollywood for that matter, are full of great potential for lies and deception....On the other hand, if you take some very deep breaths, and then take the time to build up relationships, then you won't have to worry so much about finely detailed contracts.
On the other hand....It's never a bad idea to have a lawyer check things out if it gets to a serious level.
On the other hand....Lawyers can take all the fun out of things.
Best
Midnite