I don't hate MoS as much as a seemingly huge number of comic fans do, although it's largely because I went in expecting another GL, so I was pleasantly surprised. Sure it wasn't perfect, but it wasn't the worst thing that's happened to Superman by a loooooooooooong stretch.
The problem I have is that I though MoS was a Superman origin/prequel. Afterwards would come the first actual Superman Movie- now that Zod was gone and there isn't a pending Kryptonian invasion Supes gets to be Supes and stuff. Which is why I'm worried by Batman vs Superman or whatever it's going to be called. Cause Superman isn't ready to be a crossover character yet...
As for the Affleck Batman choice, A- I don't mind, I think he's a good actor, give him a friggin chance ffs, and B- Surely in a Batman vs Superman crossover, Batman will be much more prominent than Bruce Wayne, and Batman is very, very difficult to get wrong due to the actor's performance.