1) do you recommend a full working knowledge of macros before attempting to box or can I just copy everything I need?
I'm still fairly new and am just looking into macros myself, I can clear anything (except those damned scarlet instances) at the currently level with little issue without. Simply putting your Single Target spell, your Instant spell, and an AoE spell on matching button seems to work well enough till heroic content IMO.
2) easiest and common pitfall to boxing?
I'm not really sure If I can think of anything that someone hasn't already mentioned!
3) if I can box two can I box five or is there a different learning curve?
I'd say it is a little different. First the more toons you box, the more chances there are for something to get messed up, like a toon getting caught on a wall, or one not turning in a quest. Usually not a big deal once you get used to it, the only other thing that I think makes a big difference is using a non-passive healer is quite different. But if you can manage to two box you should(tm) manage to 5 box.
4) what do you hate and groan about this hobby?
Two things. Getting ganked sucks, I wouldn't say its five times as painful, but its a bit more annoying; with cross-realm zones camping is even more common at high populated areas, such as HFP and Mount Hyjal were I try to go to do the first 20 or so quests to catch up in some slots of gear. The other thing is the reworked dungeons are a pain in the pooper! Scarlet Halls? FORGET IT! Dark Master in Scholo? On a new account with no BoAs and not the best team comp/dps is a pain!
5) what do you love about it?
Everything else. I love the feeling of it and how I can *solo* most things. Even though Dark Master took me an hour to kill, I killed him, its almost like raid progression. That feeling is always a rush! The unique challenge it brings to games is just so amazing.
6) what do you box class- wise and why would you recommend it?
Currently with the new set of accounts (no BoAs) I wanted something that could pull decent dps and not have to worry about healing. So I went 1 Prot Pally and 4 Disc Priests. They have some sick burst and you rarely die once you hit 37(I think) and get atonement. The biggest flaw in this team is no AoE till 76, and it isn't very powerful even when you do get it. Its a slow but safe group comp.
The group comp that I would recommend for your first team is 1 pally 3 sham and any healer (a different armor type would be nice). They abilities of the pally and shams (ele) has such good synergy you don't need ANY macros till level cap. Put Chain lightning on the same button as Hammer of the Righteous, Lighting Bolt on Crusader Strike, Earth/fire/frost shock on Judgment, and Lava Lash on Avenger's Shield and you have yourself and very strong as well working team!