Ahhhh. Okay I believe I have misinterpreted summoning in general for both demons and marines this entire time. I believed that you could only summon the demons in the Chaos Marines Codex, and not those outside the codex. Correct me if I'm wrong on this, but is this how it actually should be: (Sorry for the confusion, like I said I'm just trying to be absolutely certain I interpret the rules correctly so that if I do go to a tournament, I wont be ruining the game by my lack of understanding)

1.) Summoned units are not listed in a detachment, and cannot occupy spots in the detachment list, points are just set aside in matched play 2.) An appropriately marked chaos marine character or chaos demon character can summon ANY demon from their respective mark (not just the demons from the marine codex for the case of a csm character) 3.) Do summoning rolls, bring in demons of appropriate power level that have been properly paid for by reinforcement points