Hi there Garbanzo, Welcome to the forum!
One thing to keep in mind regarding memory usage is although Windows 7 does use less then Vista.. XP isn't entirely truthful when reporting how much it uses.. It runs great on 2GB of ram for sure but just remember it's a tad bit deceitful in that regard
... Microsoft did a great job fixing this problem in Windows 7 though in my opinion..
As far as UAC goes.. Since you didn't use Vista you lucked out, it was way worse then 7 is in that regard.. Win 7 allows you some flexibility with UAC though.. with Vista it was either turned on, or turned off, there really wasn't a happy medium.. and if you turned it off and on more then once it really mucked things up.. But Windows 7 now gives you the option to "turn it down" rather then completely off. I've been using Windows 7 since build 6801 and I have to say MS did a bang up job making UAC less intrusive and overall less noticeable... You say it is annoying... well it can be for sure, but in 7 I don't mind it at all, I have it turned down to the second to lowest setting, and it barely pops up... I'd suggest you fiddle around with the settings a bit and I'm sure you'll find one that fits your needs as far as UAC is concerned...
To open the Task Manager there's a slightly different key combination to use now, it is the same for Vista (and it works in XP too) Rather then CTRL+ALT+DEL you can use CTRL+SHIFT+ESC and that will open Task manager...
As far as all your hardware not working out of the box goes, just try using the latest Vista drivers, they are "supposed" to work in Windows 7 as well. If they don't work for you and there isn't an official Windows 7 driver released for your hardware yet then you'll just have to wait until there is... which will be a bit of a wait of course since 7 is in BETA stages.. but soon enough..
The wait for 7 to "catch up" in terms of hardware/software compatibility won't be as long as you think.. since Windows 7 is built off the Vista kernel. Therefore all the hardware and software that is compatible with Windows Vista is/will be compatible with Windows 7..
Glad to hear your liking Windows 7!