I feel that all criteria that you have listed can help to detect a scam project, but the real problem is that big scammers are acting like professionals and it is extremely hard to mention any of these by their attitude. However, even such projects are stealing money, so we need a better way to detect them.
Indeed, its difficult to find which is not the hoax or the better one between them because you can be deceive by their words. Some of us had some trust issue regarding about some stuffs like this, and that is the reason why we need to be cautious and attentive because they are everywhere. They take advantage on a person they think is fool enough to fall for their tricks.