Chilled to the Bone, Dampened Magic, Kleptomania, Netherwind Armor, Prismatic Cloak, and Temporal Shield have limited use in PvE content in terms of increasing your damage in the open world, but they can be situationally useful. Notably Temporal Shield can be utilized for, functionally, an extra 6 seconds of combat time against large elite mobs.
War Mode: War Mode can be turned on at level 30 through your talent window, and will give you 10% bonus XP. You will, however, be attackable by players of the opposing faction, but changes have been made so that all players have a fair shot in a fight and even low-level players can kill much higher level players, and at least not get ganked and one shotted. Note: As of patch 8.1, you can get an additional call to arms bonus with war mode on if your faction is underepresented.
These are Warlock- and Mage-only skills which can net you some money. It's not much, but a few gold is worth it. Note that Mages have an easier time with this than Warlocks as Warlocks need to be at the location for the summoning and need an additional person (a 3rd) for the group to help out with the summons. Mages only need the reagent to open the portal. While the Warlock doesn't incur a cost (except the loss of a soul shard), the Mage will typically be more successful at finding employment using this method.
An important aspect when selling transmog on the AH is that it often takes some time to sell. Therefore you will make more gold the more diverse your portfolio of items is. If you only farm one tier of gear. Lets say for example gear in the 60-80 bracket. You will be limiting yourself as the demand won’t be there and you will end up with too many items. You will end up with many of the same items for things that aren’t in demand but might sell occasionally.This means that spreading out your farming across all tiers is best, as you will get fewer of each item but more different items to meet the actual demand.
I tell you my experience. I'm leveling a priest that it's 60 now and since I have also done some instances (and I have full heirloom set with 20% experience gain bonuses) and been very ahead of the guide, I skipped some zones since they were grey quest for me, well it was a real mess. Missing quests because I didn't to the previous to enable the following. Going in a zone then realizing that I couldn't do that quest because I didn't do the starting quest chain, very unconmfortable. In short what I suggest you it's not to skip areas, or make really sure that you do all the quests required (at least) and check carefully the previous zone you'll going to skip to make sure that you won't have problems with struggling finding where to start the quest chain to sync with the guide section.
2. Once you have an interested buyer, stay firm in your price. This does not mean to never make them feel like they are getting a bargain. You can subtract 5% off the price and not be hurt as long as you still make a profit! Remember this, as that 5% may not be a big deal to you, but the buyer will feel special and might buy the item for the slightly reduced price. I can not emphasize enough that this is not the same as undercutting! Do not drop every good every time or you develop a reputation as a soft seller and people take more liberties in their dealings with you. If you give someone a constant 5% discount, then they begin to want 10% and then 15% until you no longer make a profit. Discounts are used when you feel that the seller may be pulling away and you really want to just profit and move on!