Yes, you only get cash for six schollies no matter how many you actually have open. Colonels cries about this all the time. I would normally not recommend cutting a senior (he'll be gone next year, you won't get any cash for cutting him this year, and he would certainly be far more useful than if you ended up stuck with a walk-on) but since you have eight this season and will only get money for six next year, it probably wouldn't be a bad idea to go ahead and just cut the worst two this year and try to get a small head start on your rebuild. Just my two cents.
Yes, Gunnar, you are also correct. You may have all twelve schollies open, but of those twelve only six may have the same number of years eligibility (such as six freshmen, six two year JuCos or six freshmen, four two year JuCos and two three year JuCos. Three freshmen, six two year JuCos, and three three year JuCos. Combinations like that. An ineligible freshman high school player would count towards your total of six even though he can't play at all that first season. The following season, were you to have a bunch of schollies open again, he would count as a sophomore. Should he decide to stay as a fifth year senior, oddly enough, he would NOT count towards a class that consisted of, say, six senior transfers. According to CS, at that point, he is no longer considered to be a "regular" senior and is deemed to be in his own separate class. Strange I know).