The moving wait situation is unclear, because there isn't really a way to make it black and white.
It really is a judgement call.
We try to get everyone pretty close to the same page though.
If a dog is heading for an off course obstacle, and the handlers stops the dog = no issue
If a dog is heading for an off course obstacle, handler stops them, redirects, dog heads for another off course, handler stops them = no issue.
Dog is running normally, handler stops them, then continues = suspicious and odd, but no issue
Handler consistently starts and stops the dog while running the course, for no apparent reason relating to the course = training and an E.
I know some handlers have had dogs that want to just run and not really listen, so they will do a ton of moving waits in random spots throughout the course to get their dog to pay attention and listen a bit more, done excessively it's training.
The gruff talk is pretty easy.
Imagine a child doing something in a store. You don't know the child, don't know the parent, and have never seen them before. But they're doing something they shouldn't, not life threatening, just opening a box of cocoa puffs.
If you told the child to not do that, in a loud but assertive way, it's probably not going to be an issue. Some people might not like it, but it's not a big deal in the grand scheme of things.
If you yell at them and are obviously angry and trying to intimidate them with your voice, you'll most likely be leaving the store without your groceries but a nice pair of shiny hand cuffs.
Same applies here. You can be loud and assertive, but you can't yell and try to intimidate your dog while in the ring.