For your questions:
1. I think it would be ideal to invest what you can afford to lose. It's always going to be like that. You won't know what project you would profit in but it would be nice to put money in a project that you think will moon.
2. Aside from that, I think if the information is rare, don't buy into it. It's better for a project that has concept and details.
3. What do you mean to pick your best? Did you check your link? Everything there has ended. I have seen those pairs already in Binance. If you were to pick, it should be related to a great narrative.
I edited the original post to explain this:
P.S: By "investing on launchpad projects", I mostly mean buying and hodling a token which has done its price discovery for a few weeks, not staking BNB to get some tokens.
Also, the information being rare thingy refers to information about comparing these projects, or scoring them based on their success probability. If there's no information about a project's team or roadmap or things like this, of course I'll never invest!