Team is the most important thing. There should be at least one known and real person in the team.
Fake names, fake photos, fake titles are the first signs for me.
Exactly. First thing you do is to check people involved. Best is if you know some from before. Not know know, but had heard of them and their previous projects.
OP asked question a bit strange. I would never enter any non opensource project unless would know people behind it are trustworthy and passionate about the project. So latter on there will be no signs since scams will not happen.
Thing is there are now so many good projects, you must be a real idiot to give money to scammers.