Instead of connecting an electric guitar to an amp -

... would it be feasible to run it through my mixer (on the mic in), and use an effects box instead of pedals?

Thanks!

i don't own anything you mentioned in your post, but i assume you would hook it up through a line-in and not a mic-in. i don't see why it wouldn't work, apple (actually monster) makes a cable to hook-up your guitar/bass to your mac to record into garageband.