So here's a small application written by me to instantly change realms. Instantly Logout, Instantly go to character select so on. You must run this as administrator.
Instant realm change still has a 15 second cool down server side. You can tell this because the yellow text that comes up if you try to switch realms too quickly. However its still much faster and instant if its been at least 15 seconds since your last realm change/zone change.
Hide players... well it hides all players and you can run around while they are hidden.