still a bit confused (although it's probably too late now since i manually updated). so i can't do future ota updates anymore? by placing update.zip in sd card that means it's "rooted"?
No, installing the factory update is not "rooting" it. What he meant was that since the update is already on your phone, when verizon checks it, they won't send it again. Updates AFTER 2.0.1 will install just fine OTA.
Rooting is completely different. It's removing all the "stock" options on the Operating system of the phone and replacing it with a custom OS. Once a custom OS is on, it will no longer automatically update.
Summary, the "update.zip" file is a standard factory update, you just are installing it manually and not waiting for it to be pushed. it doesn't endanger the phone or change the way you will receive future updates. Rooting replaces everything standard and will prevent you from receiving future OTA upgrades.