This whole affair has caused myriad arguments with the community, with some old-timers noting that the time-to-level increase is a joke compared to Vanilla, and newcomers sharing their point of view that World of Warcraft is slower than a lot of other games on the market. I can certainly understand both mentalities, but given that the leveling system is sort of a token process now and is already frustrating for a lot of players -- seeing it shaken up this much can't be good for the game.
Getting reputation for the new factions is going to be beneficial in different ways. Earning reputation towards the factions is going to help you unlock Pathfinder in Kul'Tiras and Zandalari. Pathfinder is nothing new so i decided to include it in here. Pathfinder will give your character increased mount speed and its account wide. Also gaining reputation will allow your character to buy gear, from a vendor, equal to Heroic dungeon quality.
So this is all from my understanding but with the scrapper it seems to be that you get materials based on the type of gear that you are scrapping. I.E I got more ore from scrapping plate gear and more cloth from scrapping cloth gear. Trinkets, weapons, and rings give different types of material and I don’t quite know the layout for that. Personally I would just DE everything as an enchanter. I stressed how important it is to trade with other players to get the materials needed to do all 11 warfront quest and you will obviously have more materials to create the enchantment that is necessary for the turn in to make trades with.
Something to keep in mind as well is that this will make enchanting materials more valuable, since it is likely most players will now simply scrap their boe greens instead of getting them disenchanted. Also redundant dungeon/raid gear can be scrapped rather than traded to the (guild) enchanter in the run. Less stuff gets disenchanted, meaning there will be less ecnhanting materials, meaning their value will rise. All the more reason to DE rather than scrap as an ecnhanter.