The shortcut is not an “approved trail.” It is a cross-country route that follows natural rock ledge systems most of the way, although it does drop down into brushy terrain in a couple of spots. I recommend staying on the regular trail instead of that shortcut, unless you have traveled it before with a day pack and have become acquainted with it.
There are stream crossings with the regular trail, but the crossings will not be problematic in August. Also, you will have larger overnight packs, and the regular trail has fewer brushy spots to get tangled in.
None of the North Fork regulars I know use bear canisters. I suspect that some guided groups may take them, though, for a couple of reasons that aren't much of a concern to the rest of us. The chance of a bear encounter is very remote, especially above Lower Boy Scout Lake. Of greater concern are marmots (the army) and ravens (the air force), and you must protect against them. A bear canister will easily do the trick, of course.
The southern-most approach you mention (red route below) is the one my friends and I always take. The rock is solid, whereas the chute proper is very loose. Some people point out "Well, that approach has some steep third class on it, and the chute avoids it." To that I would respond "If you fear that third class, you have no business higher up."
