It takes roughly the same time to level to 60th, and then skill up a gathering profession to 300.... as it does to reduce your leveling speed and skill the gathering profession as you go. That is assuming no RAF.
With RAF, the only way to skill up a gathering profession while leveling the toons, is to greatly sacrifice your leveling speed. But since RAF is a limited duration, I'd say during RAF ignore the trade skills entirely, unless you're on a new server or starting wow and cannot afford to train your toons. Even if that is the case, once you have leveled the first set, gain a bit of gold in Hellfire and then ignore tradeskills until after RAF on the other teams.
I like to end up with 1x Skinning, 1x Mining, 1x Herbalism and 1x Enchanting across the team. That way, should I be in the mood, I can gather any resource, and if the team does instances I have the option to disenchant, should the essences/shards/dust be more valuable then vendoring a drop.
I would recommend one Jewelcrafting toon across all of your teams (or possibly several, to gain recipes faster), and for as many alchemists as you can stand leveling.
I'm sitting at 19 alchemists currently (have been taking a lot of time off of wow lately), but plan on having 29.
I'm currently making 3k gold per day, transmuting gems (takes 16 minutes) via alchemy, and then using Quick Auctions, I use the auto cancel and then post features... 5-6 times between heroics or battlegrounds, over the next couple of hours. I'd say under half an hour of "working" time, for 3k a day.
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