So can somebody explain how the 4 non Playoff bowls work?

This is something that has perplexed me as well. Hasn't really been elaborated on all that well.

I THINK (could definitely be wrong) that the committee will also be the driving force behind placing teams in those 4, based on their rankings.

After the 2 semifinals + 4 access bowls...then it just goes down to the bowls and schools working it out like the past.

Orange Bowl takes the ACC Champion or top ranked available ACC team and places them against the top ranked available SEC/Big Ten/Notre Dame. MSU in the Orange Bowl talk was when they were #4 and hadn't gotten their asses kicked by Ole Miss. If State would not have been #4, they would have been #5 - the top available SEC/B1G team. The Orange Bowl ship has sailed.

Georgia Tech will either be the ACC Champion or the top ranked available ACC team, so they are pretty much there.

Mississippi State dropped below two Big Ten teams (Ohio State and Michigan State). The Orange Bowl doesn't want a repeat team so Michigan State is pretty much slotted here, even if Ohio State doesn't get into the Playoff.

The top non Power 5 champion gets a bid to an available spot. That team is Boise State. They could go to the Peach, Cotton or Fiesta Bowl. It makes sense for the Fiesta (geographical considerations) but is not guaranteed. Boise opened the season in Atlanta so I doubt the Peach gets them.

As far as Mississippi State, there are three possibilities with the Orange Bowl out of the question.

Peach
Cotton
Fiesta

Assuming the Fiesta has Boise State, they are probably going to take Arizona or Baylor. So MSU is likely headed to the Peach vs. Ohio State or the Cotton vs. Kansas State or Wisconsin. The last spot in the New Years Six bowls is up for grabs. I personally think it will be Ole Miss.

This is how I think those four will shake out:

Fiesta: Arizona vs. Boise State
Cotton: Ole Miss vs. Baylor
Peach: MSU vs. Ohio State
Orange: Georgia Tech vs. Michigan State

Now, if both Wisconsin and Missouri pull the upsets, Ole Miss is probably out - and will be put up against Georgia in consideration for the Citrus Bowl.