The tuning dictates the intervals you play laterally as opposed to horizontally (Woww their Simon, what was that !!!!). I mean you can move any distance to play interval up and down the neck however the intervals across the strings are dictate by the tuning.
This has a dramatic effect upon the runs you can and cant play.
I personally think it is easier to play slide with an open tuning though it is possible to do it with EADGBE.