Does the Dimensional Slide meet the prerequisites for the Dimensional Agility Feat Tree? If so then frankly that can be an amazing way to keep your Arcanist alive and out of harms way. Any official word or direction would be appreciated.
No.
Dimensional Slide is not Dimension Door, so it does not meet the prereq.
Now, an arcanist can cast dimension door which will meet the prereq, but it will also require him to expend the spell slots to actually cast dimension door rather than being able to use Dimensional Slide, because the feats specify using Dimension Door or Abundant Step.
Unfortunately I read it that way as well. I just was unaware if anyone had seen any updates to Dimensional Agility since the Arcanist class was published after the Dimensional Agility Feats.
Food for though...
If allowing monsters as PCs, the Blink Dog gets Dimension Door at will.
:D
Throw levels of Urban Druid in there (to get Thousand Faces) and you have someone with unlimited use, looking like a humanoid.
Seen it in player, VERY powerful.