i recon a 2foot kickboard is way way way too big. you want to have as small a kickboard as you an get away with, like 6 inch or something, otherwise half the moves will be with your feet in the same place, so don't put that many footholds on it either. having a set of footholds totally on the main board (i.e. non on the kickboard) makes for harder problems also. get really poor footholds, and make sure they are all about the same, otherwise if you've got one or two footholds that are much bigger than the rest you need self disipline for your problems not to revolve round the same good foothold, particularly on a short board. i do all my stuff purely on footholds, no hands for feet, as this keeps it hard work, and keeps the handholds clean. if you use poorfootholds then you'll get better body tension, and when you go outside or in commercial indoorwalls every time you put your foot on a handhold it will feel like a bivi ledge. plus poorer footholds means you're pulling harder on slightly bigger handholds, so less likely to get injursed than if you're pulling on tiny little holds with feet in jugs.
its worth putting a lof ot thought into your footholds particularly as they are the ones that are time consuming to replace later.
make sure your grid of t-nut holes is a ofset grid or it will be boring, but make sure its regular enough to use systems holds. also put some footholds aside in a ladder for system shit. drill all your panels before they go on the wall (you can drill several stacked up to save time). put in loads of t-nuts.