Kybucki, I have disagree with your thought on switching zones so much. That is one of the primary reasons to run a zone defense is the flexibility it offers. Zone is a tough defense to run at times, especially against really balanced teams, but its on you to change your lineup as needed to fit the defense when you plan on switching things up.
One of the key's to a zone is paying attention to where they are scoring from. Lots of 3, find out how many players are shooting 3's and what % of each playrs shots are 3's. If it's only one guy jacking them up, maybe just double team him and run a 2-3, but if its their top 3 scorers shooting like half of their shots from 3, play a 3-2. Small stuff like that is important.