Yes, 121 is safer than 135. Yes, staying home eating brown rice and celery is safer than becoming a pilot, especially in Alaska. (A pilot alone in the cockpit here has less "supervision", than one in the pattern at Boeing field, thus more opportunity to make decisions for himself, and to live with the consequences of those decisions.) It is unwise to operate a single engine wheel plane over water and not be within gliding distance to the shore, and I don't do it. A grey bearded pilot once told me to think of all water in this state like a roiling vat of acid. If you go in, chances are you won't come out.