Is there a listing available of exercises that might be substituted in place of others? For reasons like 1) don't have the necessary piece of gym equipment, or 2) dealing with an injury that doesn't allow you to do something, for example rotator cuff injury preventing overhead pressing or overhead Kettlebell holds.

Some of the form videos have some alternatives in them, but if you can't find an alternative there, a lot of the Crossfit forums will have lists of substitute exercises that you can do - I have to swap things all the time b/c I work out in more of a health club where I can't necessarily do the supersets exactly how they're provided in the programs. The Crossfit forums will also have cardio conversion charts that go across the bike, treadmill, rower, etc so you can find out the distance/calorie amount that you need to substitute. Hope this helps!