Errata says:
What kind of action is it to remove your hand from a two-handed weapon or re-grab it with both hands?
Both are free actions. For example, a wizard wielding a quarterstaff can let go of the weapon with one hand as a free action, cast a spell as a standard action, and grasp the weapon again with that hand as a free action; this means the wizard is still able to make attacks of opportunity with the weapon (which requires using two hands).
Now, does this mean that one can do full attack with two-hander then take his hand off and use Crane Wing to deflect an attack? But this effectively makes any AoO (and crane riposte one) to be made by unarmed strike? Then next turn grab two-hander and repeat?
I understand this goes in the land of rule-benders, but is it technically possible?
Yes. Just don't expect to do AoO's with the two-hander while it is held in a single hand.
Crane Wing works better with a bow, where you always have one hand free. Hello zen archer.
HAXXX.
Thank you.
Just use a longsword in 2 hands, and 1 hand off turn. You're giving up 2.5 damage. If you get a Katana EWP for free, use that instead.
==Aelryinth
Keep in mind your GM can set a limit on the number of times your allowed to use free actions to do this (in a turn).
Yes. Just don't expect to do AoO's with the two-hander while it is held in a single hand.
Well that's why you have armor spikes and a spiked gauntlet. Put spikes on everything!
You can also effectively buy a proficiency with a cracked opalescent white pyramid ioun stone, and katanas 18-20 crit is pretty awesome and 1500 gold is a drop in the bucket at later levels.