Disabling the Customer Improvement Program dialogues is a good idea but...
Disabling UAC - Stupid thing to do... Annoying, yes - but silly to disable it, as it might well save your skin - particularly if you are an IE user. Linux has the same thing implemented in an even worse way - but people don't moan about it. This is just jumping on the bandwagon I reckon.
Freeing up RAM - If you think you need to do all that to free up RAM in Vista, you are wrong. Vista uses a different style of memory management, as in it uses as much as it needs until it is used by a different program. What is the point of having 2Gb of RAM if your OS only uses 256Mb of it? Vista uses a lot of RAM to keep itself running smooth. Run a game or other RAM intensive operation and Vista will free up the RAM as necessary.
As for the other points, disable Windows Defender - its crap. I agree with that point :lol:. Don't disable automatic updates fully though - just set it to notify and not download and install without permission. That way you always stay up to date without it using resources or bandwidth.