The problem with safety is that it requires constant vigilance. All of us could be tricked on a bad day when we are tired and our guard drops. That's why those scammers manage to get to hundreds of -reps. I want to share one idea with 1000+ users.

Put the following in big letters on your trading thread:

1) I will never, under any circumstances add you on Steam.
2) After we agree on a trade in the comments below, you and only you should add me through my steamtrades profile.
3) If you ever get added by someone that looks like me, that's 100% a guaranteed scammer.

This way you don't ever need to remind yourself to verify the people who add you, as they are always scammers. If this practice was adopted site-wide (the commenting / offering party adds the party with the trade page), then scammers would have a much harder time doing what they do.

Yes, the burden of verification then falls on the party who has the trade page, but those are usually more experienced users and not as easily tricked. Also, you know exactly when to expect to be added and by who. Scammers would now have to do a lot more legwork (worry about exact timing of the invite) to very little success.

Maybe yes maybe no i dont know ( ͡° ͜ʖ ͡°)