There really is no room for anymore, let alone another main-hand slot causing more grief to the game.
Even specialist-exclusives are wearing thin now. That tells you everything there is. If anything they did a wonderful job this expansion with craft/gather end-game and they can just build on that success going forward.
Farmer for gathering. Let us do some animal husbandry as well so we can farm out mounts peaceful style. I'm hoping the new farm area lets us do this as well as grow stuff, let our minions/mounts roam freely, hell as long as its instance let us have our own house/barn in the island.
A crafter, no.
All 8 crafters are basically identical clones now. In its current form, a new crafter serves absolutely no purpose except to divide the list of recipes into 9 parts instead of 8.
They should make each DoH have unique skill/passive at least 1 perhaps, like culinarist makes all quality skill generate 10% extra quality and other doh have other passive, it will make each DOH kinda different and it will make interesting choise when doing expert crafting rotation for each DOH, the same goes to DOL just make one have higher GP regeneration while the other higher max GP or any passive or skill to make it a little different, just my little suggestion