1) That should be fine. http://www.eliteairsoftbatteries.com/
is a pretty good site, they're a spinoff of Cheapbatterypacks which is highly regarded. Anything from there should fit the bill.
2) That charger from TorontoAirsoft should be alright as well as the one from 007 (can't see the one you're talking about but I'm sure Kens stuff is good). I would really go to a local RC hobby shop however. They tend to have a greater variety of chargers as well as cheaper prices. I would highly recommend something like the DuraTrax ICE charger but they're pricey (retail of around $120 even at the RC shops), you get a lot of cool features but TBH you're probably not going to use half of them if you just want something you can "set and forget".
3) Try the iron sights first but if you want a red dot, you could get something from Canadian Tire. Probably as cheap as $20-25. You don't want magnification. Trust me on this. At most 1.5 or 2x magnification is all you'll need. No need to go higher.
4) Anything you find is good. The magpul AFG is something a lot of people are jumping onto. It's cool and all but personally I don't really like it (I haven't used it but I do use my vertical post front grip in the same way that Chris Costa uses it, basically just as a "guide" for holding it the way the AFG was designed for, but I also do the "beer can" hold as well sometimes).
5) No clue but Magpul Green label ones are cheap as hell. They're STAR rebrands and super cheap. I use STAR mags in my M4 myself, they're pretty good and I can lose them or break them without thinking twice about it.
6) You have a Low or Midcap mag. The top feed door and wheel is for hi-cap mags. Really, that's an awesome mag to have. I personally hate hi-caps (or "tactical maracas" as they're sometimes called). To load, you need either a speedloader (the "pistol mag" ones are really popular) or a "tube and plunger". (This is the pistol mag loader
) and the tube and plunger is basically what it is, a tube (usually plastic) and a plunger (also plastic) that you push BB's into the mag using. You can also use an airsoft inner barrel and metal rod or something in a pinch.
7) You NEVER use a BB loader on a hi-cap. You fill the BB resevoir first and wind up the BB's up the feeding tube. I'm not sure but it would seem like you could damage your hi-cap if you load it with a BB loader or tube/plunger.[/QUOTE]