All of those inside cuts could be made just as easily if not faster with a coping saw.
I'm not a fan of lite ply fuse sides either but for different reasons. I don't like the way it turns out under a fabric finish, it's prone to splintering, and it doesn't absorb engine vibration like balsa which leads to cracked glue joints. I think it's heavier too.
Kit manufacturers came out with plywood fuselages in order to save money. For me, there were no other advantages. The locking tab construction that a few used made for a quick, straight fuse but at the expense of an ugly finish.
carl