Can you trust other players: Unfortunately there are lots of people out there willing to get ahead to your detriment. That said this business is a lot easier to navigate if you have people you can trust. Trust for information, helping sell (and buy) deals, take on projects, expand horizons, etc. These relationships will take time. You can't force them.
Stealing Your Deal?: LIke previously said. If they deal is a deal you should be able to get it sold. I am presented many "deals" where the perosn with the contract has signed it based on ARV x 0.70. Many times this is not a deal. If the ARV is 300,000 and the rehab is 200,000 - is paying 210K a deal??? While that is an exaggerated calculation - hopefully you see my point.
Is your contract legit? Contract law is strong in the U.S. If you have a legit contract you can enforce it. Sometimes it may not be worth your time but you have the opportunity. I am surprised no-one has said it yet - but spend an hour or 2 and sit down with a local real estate attorney. Before booking time be sure to ask qualifying questions regarding their knowledge.
The information you get from this will be priceless.
I did this myself a number of years back. Lucky for me he let me record the entire conversation. I refer back to it all the time.
I am happy to share the audio file with you. Just message me. The attorney is a Colorado-based attorney. However much of the information is true for many parts of the country.
SUMMARY: Don't waste energy worrying about people stealing the deal. If you come across a scoundrel (which will happen) just learn from the experience. Hopefully it doesn't happen much to you.
For the record - I have never had anyone steal a deal while under contract. Like previously said - if it falls out of contract then it's no longer your deal.