1. Whitepaper
2. Team and partners research
3. Roadmap is clear or not
4. Check on reviews website like icodrops and icobench
Yes, I agree with all of your advice, but I would not hesitate to trust the information that is posted on the sites icodrops and icobench. It seems to me that good reviews on these sites can be bought and there are already a lot of topics on the forum where the lack of reliability of these sites was discussed.