I must admit, this is better than most movesets we see on Pokebase! Congrats on actually making logical choices! :P
There are a few slips though. Marowak really does need Earthquake. If you can't get it on him, then Bonemerang is the next best thing, but it's slightly inaccurate. Bone Rush would be interesting, since it's better at Sub-Breaking, and with a little luck, it can be stronger than both Bonemerang AND Earthquake. You probably see what I mean though.
Scizor needs more Technician abuse. Dump Iron Head for something that can do this.
Palkia needs Ice Beam to counter his only weakness. Dump Draco Meteor to make room.
Get rid of one of the Ghost moves for something to cripple. Swagger works well with Giratina's enormous Bulk, and Thunder Wave helps to slow down speedy foes. Use Thunder Wave for Giratina-O, and Will-O-Wisp for Giratina-A.
Sunny Day set for Charizard? He's a Fire-type, so that works well. I won't recommend an entirely new moveset, since Sunny Day Charizard is perfectly viable. I'd just take out Blast Burn for either Earthquake or Roost. Take your pick.
Your Gallade is pretty good. Nothing really lacking of it, so I'd leave it without changes. No sense in fixing something that isn't broken, right?