When writing your idea and submitting it using the Submit idea screen I usually approve or reject an idea based on the following five criteria.
I think about 30% of the ideas that are submitted by players are added to the game, so please do not expect that because you have written an idea it will automatically be added to the game.
I do not show favourtism to any player or players when submitting ideas so it doesnt matter who you are, so long as your idea doesnt break one of the five rules at the top it may very well get added to the game.