On a rough guesstimation, I\'d say...
A. No. Sony will probably provide their own network that\'s accessable through the internet. Since there are no 1-800 or other toll free numbers for broadband modems (no dialup), and since even Sony dosen\'t have the resources to wire this whole country, I doubt Sony will care weither you use their service or someone else\'s.
B. I\'m sure it will be. There\'s a lot of gaming possibilities that can be done offline on a HD such as level editing and skin making. Some games may eventually require the HD so that it can preload levels and cut loading times down to close to nil. Xbox is already touting the feature since their HD is built in. Then you also have to remember that the PS2 can connect to your PC or MAC via it\'s USB or IEEE firewire ports. This could allow you to download presorted MP3 librarys and other goodies for your games.
C. As long as you have a place to plug your modem in down in your basement, I don\'t see why you\'d have any trouble. Even if you don\'t, it\'s just a simple matter of drilling a small hole and running some wire. Really no more difficult that brining a Coaxial or CATV wire up through the floor from downstairs, use on another TV.
D. Tough to say. I doubt it\'d be any more than 20 bucks a month for access to the server. Then you have your DSL or Cable access bill seperate, but on top of that.
E. The modem and HDD will simply slide into and lock into the expansion bay in the back of the PS2. Then just plug your modem into wherever it is your highspeed internet access comes in from. It\'s that simple.
F. Tough call. I would think yes because of the way Sony groups regions. (USA, Mexico, Canada are all North American Territory) I may depend on just how "Wired" Canada is compaired to the US though.
G. One big Sony network from what I understand. However Square, Capcom, Konami, and all the other major players in the video game scene will probably all have their own specialized servers that you have to pay seperate to access. Squares already said that they are looking into the 5 to 10 dollars a month fee for PlayOnline network.
Now, I\'m not saying anything of what I wrote is true. This is my educated guess of what\'s going on from what I\'ve heard from Sony and their representitives. Until they make an offical announcement, just take it all with a grain of salt.