View-only leagues are a no-no for me, but I suggest you take a look at this thread before setting up your save:
It's from two years ago, but almost everything in there remains current.
About the match detail, once your game world has been created, there is a menu option called Detail Level that will allow you to change what leagues get simulated in full detail. Basically, the matches in the loaded leagues can be simulated in two ways. There is a basic simulation that is the default for most leagues, where the match result is simulated based on the reputation and the abilities of the teams and players involved, but there isn't any actual football being simulated. You can also choose a full simulation where the entire match is played out, just as your own matches get fully played out, which of course requires a lot more processing.
Knowing you somewhat from the OOTP forums, I know you will get the urge to simulate every league in full detail. I have a poweful CPU and want realism as much as you do, and I still have to conform myself with about 30-40 leagues running matches in full detail because otherwise it is too much processing.