Sakari's page

That rule is mentioned under the general Conjuration rules.

A creature or object brought into being or transported to your location by a conjuration spell cannot appear inside another creature or object, nor can it appear floating in an empty space. It must arrive in an open location on a surface capable of supporting it.

I don't usually use the books so I can't give you the page number, but this link leads to where it appears on the SRD.

The Blood Steed trait is probably what you're thinking of.

The 5th level Bard ability Lore Master lets you take 10 on any Knowledge check at any time. Elves have a racial Intelligence bonus and can take a feat called Breadth of Experience, which gives a +2 Bonus on all Knowledge and Profession checks, so an Elf Bard would probably serve well.

Yes to all questions. Power Attack is something you choose to apply once you start making melee attacks in a round and its bonuses and penalties then last for the whole round, even off your turn.

CMB is basically another type of Attack Roll, so any bonus you have that could be applied to whatever weapon or limb you make the CMB roll with will apply. On another note, certain bonuses and any penalty to a creature's AC will also apply to its CMD.

No, but among the animal companions it is the highest. Some of the other dinosaurs have 10s or 12s, but if you don't want a dinosaur there aren't many options.

If you're going for an animal companion, the deinonychus has a 14 Charisma.