Past 250 Skill
Once you hit 250 skill you’ll need to get the rest of your recipes from the Auction House or find them off monsters. You defiantly wanna find the Wicked Leather recipes, for they allow for quick and painless leveling into the 300 range. Pay attention for them and buy them as soon as possible. It is common to pay 5 gold for a good 50+ level leatherworking recipe.
Dependencies on other Trade Skills
The only dependency you will have on other tradeskill is Engineering. At 250 Engineering can make an item called a Salt Shaker. This allows you to create Refined Deeprock Salt from Deeprock Salt. The reset on creating a single Refined Deep Rock Salt is 3 days. The Salt Shaker is reusable so you’ll only need one of them but if you want to create refined deeprock salt at a faster rate, get a handful of Salt Shakers (each have their own reset time).
Though you aren’t very dependant on other tradeskills, they are dependant on you. High level bags require leather for creation and a lot of weapons throughout all tiers require forms of leather. So you can always find a buyer on the Auction House for your leathers if the price is right.
This can be a benefit and a curse considering you will always be needed, even after you may have started an alt and do not have interest in using your Rogue to farm leather. Cough Cough.