my 2 cents worth.
the four game red shirt rule wasn't written to facilitate transferring. It was written with the hope of keeping younger players "engaged". It also would help older players who are injured early in the season, ie/ Honas (sp?) and could be used by players coming back from a season ending injury last year. We had a lineman that came back and played in the last 3 or 4 games so he could be on the field at the same time as his brother. That cost him a year. If he had a redshirt left it wouldn't have.
the midseason transferring is an "unintended consequence" of the new redshirt rule. But it didn't change any of the "old" rules. Players have a five year clock.
Unless a graduate, you sit for a season at your new school. you can't sit at school A, transfer, and then play next year for school B. That's why TG split in such a hurry. He need to get enrolled at his new school for the first semester. He is sitting this season and can play next year. Once he become eligible his five year clock will limit him to three years of playing for his new school even through he never played a down for Nebraska.