The Game Planning Forum is for those DM's who have ideas but need input or feedback from potential players. Often times things being discussed will be system choices and genre preferences as well as play styles and anything else that falls under "brainstorming". Debate should not deteriorate to the level of 3.5/Pathfinder, 4E/3.5 or big five type arguments.
Interest checks are redundant, if no details need resolving then check for interest with an advert, it's far more reliable. You are free to run an interest check if you wish but please don't put that in the title, instead describe (very briefly) the game concept.
Recruiting nor submission of applications are permitted in the game planning threads. If the game is ready to run the usual option is to create an advert in the Games & Ads forum. Members who express interest at the planning stage frequently don't join that game; however if you wish to avoid advertising then issue invites via PMs.
This forum can also accommodate calls for replacement/co GMs or any other request for GM (although success of "player seeking GM" adverts is generally low). Please indicate in the thread name if you are seeking a GM. You may also find a Mordae's GM rescue thread in the GM workshop.
Once the game is sufficiently formed that characters are being developed a new game forum should be created by the GM.
GMs who initiate a planning thread should close the planning thread when creating an advert.