Many people hate it and others praise the UAC. Personally it does not bother me. It is an extra piece of security and will flash up when attempting to install something...this you already know. However, it will also catch things that you did not ask the computer to install and this is were the purpose of the UAC comes into play. For most, I think it is just an annoyance because most computer users are not in the know and just click OK on anything that pops up...like my dad
Others in the know see it pop up for something wanting to install and say WTH I did not ask for that...possible compromise caught by the UAC. I can say it did it for me once and it was a 'come on' anti-virus program...you know the one that does a fake scan in about 2 seconds and says your hard drive is loaded with this and that plus porn. It flashes and goes crazy....here load this up for help....blah blah blah....knowing it was complete BS the UAC popped up and stopped the download, asked if I prompted to do this. Of course not and I cancelled out all of that crap. So, yes it does serve it's purpose. I'm sure my dad would have clicked yes to all
But honestly, most times I mess with my computer I might have to click the prompt for the UAC perhaps 2 times. Those two times are for say cleaning up internet clutter or defrag. You see, I do not load up programs all day so it does not become headache.
I do not believe there is a safe list and I know you can turn it off in Vista. I'm thinking 7 has a way to turn it off also.