/createkit - not add new 1.9 potions, and potion arrows nbt tags in the config.yml.

Please http://pastebin.com your config.yml

EssentialX not support new potion nbts, and arrow potion nbts(?)

EssentialsX does support Potion NBT data via the /give command, but the /createkit command doesn't do that, at least not yet. So you'll have to insert the NBT yourself:

1.9 fundamentally changed the way some items work by introducing NBT tags as opposed to limited item damage values, /give SupaHam tipped_arrow 1 {Potion:"swiftness"} will give me one Tipped Arrow with a default swiftness effect, click here for a list of Potion types.

Alternatively and more complexly, you can use CustomPotionEffects to define custom effects: /give SupaHam tipped_arrow 1 { CustomPotionEffects: [ {Id: 25, Amplifier: 1, Duration: 200} ] } will give me one Tipped Arrow with a levitation effect, amplifier 1, and a duration of 200 ticks (10 seconds).

For more information, see: http://minecraft.gamepedia.com/Arrow

How to use new potions, and potion arrows on [buy], [free], [sell], signs? and on kits?

You can't do it for signs at the moment. But for kits you can add a command See the wiki for more information.

could this be leading back to Vault by chance? Im so not enjoying even looking at trying to get my fork of vault to handle it but Im hoping to. (but I do got the new mats already PR'd that up to Milkbowl)