1. If the red circles were client side instead of server side this wouldn't be an issue.
2. I've noticed that wired/wireless makes a difference.
3. I've noticed that if my wife and I are both playing Titan HM, she has a terrible time getting out of plumes, she'll be far out of them, but still get hit, I know because I watch her screen. I don't notice since I'm tank, and don't have to dodge. When playing alone she has zero issues on same hardware.
4. I'm on a squeaky clean network with plenty of bandwidth with an above average firewall, so multiple packets coming from one IP must confuse SE servers, or are not serviced correctly.
5. Game is too reliant on dodge, rather than skill. IMO