Wow, that's an odd way to format a post.
No, the "bonus" for scheduling teams with the same O/D scheme is minimal at best - that's not a concern you should have at all when scheduling.
As for your first question, are you asking how much more your players would improve if you have them 18-20 minutes instead? In that case, they'd improve 20-33% faster - until you hit 20 or 25 minutes, more minutes means correspondingly more improvement.
If you're asking what kind of a boost players get from WE or HS GPA in terms of IQ improvement, the range can be found in Iguana1's IQ practice chart, found
here.
But remember, there's a new engine out, so nothing's for sure.