I'm pretty sure that on the begging of season you know all changes that will be implemented, so my proposition would be, why don't you shut down the site for, let's say, one week in the off-season period and implement everything that you are planning to do, test it for confrontation, put out whats need to be put out immediately and freeze what needs to be put out after allstar week (make a backup of core system with those changes), and when everything works fine, open the site for public again. I'm not sure for other users, but for me that week off is absolutely acceptable. Probably there would be an issue with advertisements, but it's probably solvable.
It is not so important how high can someone jump, more important is who is the last one standing
