unclevic - can you actually find instances of teams like Boise, Kansas, Air Force, Iowa St, Troy St actually winning enough games/championships/high bowls to qualify for elite status? I would be surprised if you find any sort of consistent run of success for those teams in a mature world.
Why does this have to be overcomplicated? All that really needs to be done is to take the elite distinction out of a sliding scale. Make a dynamic prestige system where (and this is just arbitrarily using a scale to 100) a non-BCS school can range anywhere from 30-70, and a BCS school can range anywhere from 55-100 or so. All you need is some overlap to allow for good non-BCS and bad BCS programs, just program in some kind of multiplier to determine non-BCS prestige as compared BCS prestige. No elite distinction needed. It works at all the other levels without an elite distinction; it should be easy as heck to implement at DIA. No need to clarify which schools are elite at which times; just leave it like all the other levels, where owners can figure out who the "elite" programs are by looking at the level of recent success.
Then all you have to do is announce a date when you're switching to the new system (probably something like 3 months, aka 2 seasons, in advance) and say "at that point, DIA will switch over to an elite-free prestige system, and prestige at that point will be computed the same as other divisions, with a .75 multiplier applied to non-BCS schools to determine their prestige." If an elite has been very successful recently, nothing changes; if the elite has been average, they'll be looking at lower prestige. And so on and so forth for non-elites; if someone like Rutgers has 4 conf titles and 3 level 5 bowl wins in the last 5 years they'll probably have a very high status.
Then, you tie firings to prestige in an inverse relationship; the higher the prestige, harder it is to keep a job. WIS creates levels within the prestige (IMO they should be hidden levels, like prestige itself, but that's debatable - you could have an AD send you a message that says something like "due to our recent success, we have very high standards/sky high standards/average standards, etc.) and when the prestige crosses that line the job becomes harder to keep. You can leave the old "prestige doesn't change for first 2/3 years if win total/WIS ranking goes up" or whatever, but clearly the standards in general have to be toughened.
This could be a little tricky; you probably have to judge the coach for hiring/firing based on what prestige was when he got the job (aka a coach starts with 100 prestige, so difficult to keep the job; he has a bad season, prestige falls to 90, suddenly the job is technically easier to keep because prestige has fallen) or you just have to lag the hiring/firing prestige like two seasons behind real prestige (team reaches 100 prestige in season 41, but firing standards don't reach that toughest level in 43 or 44, for example).
So I hope that's clear enough; others can flesh it out or ask questions if it's confusing. Making fluid elite status is easy, because it just means mirroring the other levels; it's making the firing/hiring standards just as fluid that will be tougher.