would a vorlon have natural attacks?
Yes with all of those tentacles I'd imagine they are VERY good at grappling. As for natural attacks, probably only 1d4 per tentacle. As for total #of attacks, 4 "arms," 6 "legs," and 1 "tail." Whether you use all of them or just the "arms" is up to you.
do they keep phasing without tech?
If they do phase, it will have to be a supernatural ability only usable x times per day, and only after x number of HD.
do they have sight or blindsight?
I'm going to have to go with blindsight on that one.