and then only once per 7 days per board.

If your touring and you'll be wanting to advertise at least 2 weeks ahead of time, you could potentially have overlapping ads on multiple boards.  

If you live on a state line like I do, I am available in Alabama and Georgia, so I post usually on Atlanta and the "Other Cities"board.  It can happen absolutely yes.  

If your touring you have to put the dates in the headline of your ad.