This isn't really a suggestion for SRB2, but I'm posting it anyway. Reconfigure the Suggestions process the same way as Bug Reports. That is, instead of a massive, bulky thread, make it into a subforum. Then, the mods can attach prefixes to each suggestion, such as "Assigned Suggestion", "Used Suggestion", "Invalid Suggestion", "Duplicate Suggestion" and so forth.
It really makes sense when you think about it. The Bug Reports subforum seems to have made it a lot easier both for people to make their discoveries heard and for the devs to address each one. I bet that we would get the same kind of benefit from doing that to suggestions, too.