1. They removed /follow in battlegrounds a few years ago so it is not longer viable.

2. They had a Black Friday sale of wow for $5. You'll have to buy the base game and then the expansion. I believe target was offering it for $39.99 at one point.

3. Paladins, DKs, and Hunters are good. As I said in 1, /follow is removed in BG. However, World PvP is pretty good due to World Quests.

As for farming gold, I would roll dual gathers - mining and herbalism. Each node can be tapped by 10 different toons.

That means all ten of your guys will be able to mine/herb a node once and get loot.