Happ was worth his salary based on Fangraphs this year, so I'm not sure why everyone is going crazy about keeping him. It's better to have an MLB starter as the #5 starter and let Sanchez/Norris prove they are ready rather than just sticking the latter two in the big league rotation and expecting to get good results. Keeping Happ is common sense. Sanchez and Norris will be in the 2016 rotation anyway (Happ and Buehrle are FA's and Dickey has a team option). No need to rush them.
The key for this team will be what Alex does with 2B and LF. Unfortunately he will keep Reyes at SS, which sucks, but get an improvement at 2B (or 3B) and improve the OF situation. Alex going after relievers isn't a surprise. With Janssen, McGowan, and Santos leaving, and Delabar ineffective, they pretty much only have 2 dependable relievers (Cecil and Loup) if Sanchez is moving back to the rotation. They'll need to fill the bullpen up regardless.