If you're using a rules system where polymorph changes your creature type, then this is correct. However, since in PF you're mostly just taking on the appearance/shell of a creature but actually becoming it, iirc you do not change creature type. So even though you look like a pixie, you're still an Ogre Mage. Thus FE applies.
I disagree. Where does it say a Ranger needs to be aware his foe is a favored enemy to get the bonus? I have never seen such a rule. I've only ever seen DMs on messageboards unnerved by the lack of such a rule for some reason.