#1 They're completely different things. And no -- Desktop Ubuntu (like you'd run on a regular PC) is right where I expect it to be right now, going up against the likes of Microsoft and Apple. Ubuntu is going up against decades of entrenched locked-in users, stuck with Microsoft -- it doesn't matter if Ubuntu is the greatest thing since sliced bread, it can't beat Microsoft on its own turf, no matter how much better it is.
But then, it's not supposed to -- the founder himself has said this, time and time and time again. However, it doesn't matter in the long run -- the next generation of computing devices is already shaping up to be a non-Microsoft world, be it smartphones or tablet PC's (whenever the hell they finally get around to marketability ).
#2 To me, Ubuntu is just as easy and dependable at those things it was meant to do. If you're looking for it to do the exact same things as Windows, look elsewhere -- it was never meant for that.
About Debian -- Ubuntu is free to do with Debian whatever it wants, just like Debian is free to do whatever it wants with other GPL code. That's the way it works. Ubuntu's relative "success" (at least in the fact that we're sitting here talking about it) means, to me, that it's doing something that maybe Debian couldn't or didn't want to.
#3 Like I said, YMMV. For the things I do with Ubuntu (browse the web, watch videos, listen to music) I never have any problems. There's nothing to it. I've installed maybe 10 programs over the course of a few years, since I started with Ubuntu. For the things I do with Windows (install games, play games, update games) I have problems from time to time -- not a massive amount, but still a good bit more than Ubuntu.
However, I don't expect you to believe me -- I don't believe half the hardware specs people say they have on this site, either.
Dude -- I got this. Go take five.
the problem with ubuntu is that they DONT GIVE A DAMN THING BACK TO THE LINUX COMMUNITY, and they insist on making everything possible as noobiefied as possible, they also refuse to OPTIMIZE THEIR SHIT, ubuntu is like pre-sp1 vista to be honest, its got potential but its so slow and annoying to use that most people will not want to deal with it and will just move back to windows thinking all linux is as laim as ubuntu.
honestly try VectorLinux6 or Wolvix or any other slack based distro and then try and say ubuntu isnt crap.