I have an issue or two with these.
1) The internet back then may have not been as good as it is today on mobile device, but it surely didn't suck on some device, specifically Windows Mobile devices of yore. In most cases I was able to go full webpages(at least I did when I had my old WM device, which sites recognized as IE for desktops), but then that slowly started change as more and more mobile sites popped up.
I had a Samsung Blackjack. One of my favorite phones at that time. I also had a RAZR from Motorola. The BlackJack was better at pretty much everything, but RAZR had iTunes integration (albeit fair integration). Texting was better on the Blackjack, the web, and of course the few apps I used. But, in general (to me at least) it lacked that pop. Was way too windows'y (if that could be a word) for a phone. Clunky would be my better choice of word (not that all WinCE phones would be like this). Web was "Ok" IMO, better then most (Good screen), but not like the iPhone and Safari. Not even close.
4) I can't say for the other platforms really, but there were many apps for WM device, though many were good at best. I even remember playing an EA Tiger Woods Golf on my old HP iPaq Pocket PC.
Most def, but IMO the HP iPac and others like it were exceptions. Basically a better PDA/MiniPC. More in line of what the iPhone ends up being (better done though), but MUCH closer then say a black and white Treo (even the color ones). The bigger touch screen made it pimp though (iPac), and it was more inline to what was the palms before it, or Symbian Nokia's. At that time, lots of idea's, and different designs. Now, everything is IMO a copy of the iPhone. Which is why I think Apple is so aggressive in there patent lawsuits. As pretty much everything is finding away to look like there products. I mean, back then those devices were quite "ugly", and not so much stylish as they were functional.
6) I will give you that one, syncing my old WM Palm and Samsung devices to my iBook and Macbook Pro(on OSX) was a bit of a pain as I had to use third-party software. Under windows it was a bit better, and at the time like native Outlook support as that was the app I was using for email. That said I prefer ums and the way the iPhone and Android devices do it these days.
100% yes. Good god, before time was time, this sucked. Outside of Active Sync (cabled). We had too much to use to make this work right. And even then, new phones didn't work right away, or had to get an update to make this or that connect fully to this or that. Sucked! Now, life is pretty good across devices. And certainly getting better (no cords!

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7) One could argue WM was more of a pocket computer than iPhone, because of the sole fact it gave you a full file browser(with access to all folders without the need of jail-breaking for rooting), like you would find on an desktop OS.