Use a socket, (make sure it`s the correct size, you don`t want to round it off) on an extension and very carefully turn the motor over (if you can).
Off the top of my head I cannot remember the direction the crank runs in normally but I reckon it`ll be anticlockwise. That makes sense because the cam chain tensioner takes up the slack run in the cam chain and it`s on the back of the block. If I`m mistaken some other members will correct me on this.
Best keep to trying to turn the motor over in just ONE direction, I`m sure it`ll be anticlockwise. If you try rocking it back and forth and something`s worked loose you could do more damage.
I would try to turn the motor over with the cam cover off, so that you can see the cams turning, valves actuating etc too.
If it`s requiring more than firm pressure on the ratchet handle or there`s any type of grinding, clunking or snatching, firm resistance etc, you can assume there are some problems that require the motor to be looked at carefully.
That will, at the very least, mean the sump off the bottom of the motor.
Oh and yes, make sure the bike is in neutral.
Edit:
Reading back through what you`ve already posted I`m going to stick my neck out here, I`m wondering if you`ve had a partial seize in the bores due to the excess petrol `washing` the oil from the bores, that could have caused her to grab up and lock the wheel.
The more you try to turn the motor over the more the piston, rings and bores could gall up and become harder to turn over, in fact you could actually end up causing more damage but you do need to find out what it is so do everything `gently` just now.
Any bike shops or dealers close to you? A quiet word with the technicians could well have some kind hearted soul (most decent bikers are) dropping by your place in a lunch hour or after work to take a look at things for you. It might also get you the offer of a `homer`, meaning someone would offer to help you repair it outside his work hours and the extortionate prices dealerships charge too.
