Some of these could not be answered without a device, but I will take a shot at a a few of them.
The cloud is the same cloud that your Kobo WiFi uses to sync across devices. It is only for kepub books as far as I know. I sync between my Android phone, the desktop app, and Touch now. The stats for anything I read (including sideloaded books) sync as well and are reflected in reading life.
It comes with a browser (heck even the Touch has a rudimentary one) so surfing is not an issue.
I have no idea how expensive subscriptions will be, but you can subscribe to magazines using any app that works with Android 2.3.
Since Kobo will be selling the readers as well, problems getting it should not be an issue if you are in the US or Canada.
Pulse is entirely optional, but I would expect that the data that makes it work will also be used by Kobo for their own purposes--knowing Canadian privacy protections, it will be anonymized (well unless they go for illegal).