Evasion Clause Question

Does it only ban moves like sand attack and double team or does it apply to things like sand veil and ice cloak?

It doesn't ban sand attack or the abilities. Simple Question, Simple Answer next time.

It also doesn't officially ban Brightpowder or Lax Incense, but some people will bitch at you using them. Any boosts gained from Metronome or Acupressure are legal.

Even though it doesn't ban Brightpowder or Lax Incense, those are still banned if you're playing a no hax item game. As far as I know, hax items are allowed in a standard game (SubChomp), so if you want to ban them you have to make sure your opponent is clear on that (which you do with rules in any game anyway).

Questions like these should go in the Ask a Simple Question, Get a Simple Answer thread, found here: http://www.smogon.com/forums/showthread.php?t=33546