Not much more advice on using crutches, but some recommendations given your current situation.
if you haven’t already, get a temporary handicapped parking tag. Even if you’re not driving, this will allow whoever is driving you to park closer, and thereby minimize the walking you will need to do.
if you are doing your own grocery shopping, get one of those electric shopping carts (provided by the store). And don’t forget to ask people to grab stuff from the shelves for you (better than getting up/down out of the cart).
if you have ANY business with the DMV (or motor vehicle dept equivalent) DO IT NOW, while you’re still on crutches. You will skip past all the lines and go straight to the “handicapped” counter. Huge time savings.
If/when you’re interested in hearing about the “bad” news once the cast comes off as to what comes next, let me know.
Nope - a knee walker looks like a scooter. It can be hard on the knee (I imagine the iWalk could be as well), and required me to learn some techniques for getting past rough sidewalk spots - otherwise it would hit a bump, the wheel would stop, causing the whole system (scooter + me) to continue on. Despite that, I think it was better than the iWalk - for me - because I would probably have tripped myself.
Boot: Maybe not as much support but if you use the shower chair you shouldn’t need to hobble at all. The thing I really liked about the boot (they never put a cast on me) was that when I was lying down, I could take it off and let things air out. The last time I had a cast, I was 6 years old - and I remember it being pretty miserable.