I think that it is time that the forums have been cleared out of all of the topics that have been locked/not posted on anymore.
BUT: I think that anything important (Game/Forum Help, Staff Topics, etc) should stay. Keeping the help topics would be extremely helpful for everyone!
I think that the Forum Games, Old Preset Shops, Old Leaving Topics, etc. - just things that are not really useful to keep around anymore - ant I think that especially cleaning the forum games would allow people to create new/interesting games! Often people will make new games that get mistaken for being too similar to one of the old games that have not been posted in ages.