The Mindchemist adds his INT mod twice to his knowledge roles. As INT his one of his main stats he also has a good amount of skillpoints per lvl.
You could even take the Vivisectionist Archetype additionally and actually have a good Rogue.
Furthermore you could dip one LvL into either Lore Warden or Dervish Dancer Bard? And get all Knowledge Skills as Class Skills.
You won't miss out on Sneak Attack Damage because of this feat
You could also take traits that add Knowledge skills as a Class Skill if that suits you better.