So I have browsed the issue and it looks like this has been argued a few times. I am currently arguing this on another forum and I think it's time for a serious ruling.
Rules as Written:
"A fly skill check requires no action, as it is generally part of another or a reaction."
Previous to stating this it has the following:
"Flying maneuvers:
Fly less than half your movement rate: DC 10
Hover: 15..."
The Fly spell states "Flying is no more difficult than walking" and then refers you back to the fly skill.
Analyzing every bit of everything that mentions flying it looks like we get the following:
Flying ALWAYS requires an action. The act of flying is an action "no more difficult than walking."
Hover is part of the flying action. If you can't take actions, you can't fly... therefore you can't hover.
Any condition that denies you actions, RAW, denies you flight causing you to fall.
Because flying is always a move action, you can never take a full attack action from the air unless you charge and have pounce (or similar).
This is how it looks going over every inch of the rules as written.
If this is NOT rules as intended, or if I am misinterpreting things, please let me know.