In my opinion, if you’re going to keep making things as an engineer you either need to have mining or you need to have enough money to pay the outrageous prices for metal in the auction house.
I actually enjoy mining. At first mining is fairly easy. Copper is abundant in the starting areas and we even get skill points for smelting copper. But after copper turns gray skilling up becomes, shall we say challenging, until we can mine iron. Iron becomes fairly common in places like the Badlands and around the ogres and snow yeti above Southshore. I have a new hunter that can no longer get points for smelting copper and I expect even gaining skill from mining it won’t last much longer. I’m rather dreading this dry period, but I’ve gotten through it twice before so it’s just a mater of being patient.
However, if you truly don’t enjoy mining then you should give it up. We play this game to have fun and if your not having fun, well, there you go. If you are looking for a different gathering profession you’re left with only two, or possibly three, choices.
Skinning is great because you don’t have to do any extra running around. If you kill a skinable mob all you have to do is click it to skin it. The down side is that you don’t get a lot of money per stack of leather. You make your money in bulk sells in the auction house.
The advantage to herbalism is that plants are more abundant than mineral nodes. And many types of herbs sell well in the auction house. The down side if you still have to hunt for them and with so many varieties they can eat up a fair amount of your bag space.
The third option is to take enchanting for the sole purpose of disenchanting. Skilling up enchanting is an expensive proposition. And you can do so if you like. But one of your options is to use enchanting as a gathering skill. When you get quest rewards you can’t use or you have old gear you would normally sell to an NPC you could instead disenchant it and sell the dust and shards you receive in the auction house.