Too many suggestions get suggested multiple times, with either little to no detail or repeated ideas from previous threads. I suggest that somewhere in the thread creation process, the forum should direct you to topics similar to your own. Steam support does this: if you say that you are making a support request in TF2, it will link you to a "FAQ" section of the support with other people's problems.
Example:
-Player "x" wants to make a thread about making changes to the energy system.
-They title their thread "What's wrong with mist energy."
-A window/message/something pops up, saying "other users have created suggestions about the same topic. Please visit them to see if your suggestion has been made before continuing." It would then link you to threads with keywords like "mist energy", "crystal energy", "elevator cost", etc.
Generally I don't disapprove of "newcomers" posting their somewhat irrelevant or otherwise redundant posts on the thread, as long as they do not rage, think they are so almighty etc.
Generally I disapprove of people who think they know about the game, but are in fact ignorant and narrow-minded...