Well I grew up in a college town (Blacksburg, VA/Virginia Tech) and still live right down the road so I'm a college football fanatic. I actually went up to South Bend the other year when VT played the Irish, which was definitely an awesome experience! That's cool that you still keep up with college football and its a great year to be a Irish fan lol. I'm not sure if I'm fully understanding your questions, so I'll try my best to answer them and hopefully they'll address what youre asking.
1. As mentioned before, I haven't actually done the conference realignment myself, but as long as you follow the guide, the conferences should be pretty much what they are in real life, but without the new teams. After changing the conferences, implementing the 2018 schedule file, then the teams will be in their current conferences with their current schedules.
2. So for the playoff system, there is a way to do this in the editor as well, which is awesome although its even more work in the editor. There is a thread that shows the process for this which I will post below. Essentially, you will be removing one bowl game that you dont care about and use this extra bowl game as the "National Championship" and you kind of have to do some team/bowl shifting to get the correct seeds in the right games (Rose bowl, cotton bowl, etc.)
https://forums.operationsports.com/f...e-modding.html
Just let me know if you need anymore help!