Simple Q&A Pathfinder (By RAW) I

[Keneth]

Can you also as a free action change your weapon to the other hand (that just made a claw attack) and make your second claw attack with the, now free, hand?

This one is up to the DM's discretion as he's the one delegating how many free actions of a certain kind you can do at any given time. There's a good chance he'll say no.

Q92
Let's say you're a half-caster, such as Alchemist, Bard, Inquisitor, Magus or Summoner. By default you can't use spell completion items (aka. scrolls) without a UMD check, even if they are in your class' list.

Actually you can use any scroll of the correct type (arcane or divine) assuming the spell is on your spell list. So a magus could cast a scroll of shocking grasp that was scribed by a wizard. If the spell is not on your spell list, if your ability isn't high enough, or if the scroll is not of the right type, you are required to make a UMD check.