I was keeping the eye open and moving the Beholder t the shaft tilting and firing 3 rays then on second move tilt the other way and move till I was once again over the hole but looking downward. IF you're saying I can only fire 3 rays before positioning the main eye downward then what happens if I turn upside down so all my stalks are facing down the passage on the first pass then shift the eye the other way so the main eye is pointing down. Do I get to fire all 10 eyes before the antimagic?
The main eye is either open or closed during its round. You don't fire the eyes before or after closing it. You either fire them while the central eye is open, or while it is closed. But if the eye is open, you cannot fire rays in the direction where the central eye is facing. So yes, if played correctly, you can fire all 10 eyes at once.
Can we assume the player turned to stone that falls 40' to the floor breaks apart and dies?
No, there are rules for that. The basic rule is simple: 1d6 points of damage per 10 feet fallen, to a maximum of 20d6. So that's 4d6 damage. Stone has a hardness of 8 (15 inch thickness), and a Masonry wall (1 ft. thick) has 90 hitpoints. But the Statue spell states that the subject keeps his original hitpoints, so that is what I would do. Allow the player to keep his original hitpoints, and give him hardness 8. He takes 4d6 damage, and he only crumbles if this reduces his hitpoints to 0. (Not likely)
If the statue is damaged, the subject still has these deformities after returning back to his/her normal self. So if the arm of the statue is severed, then that's a severed arm.
With the eye stalks attacking as a free action then I am not sure what Flyby feat gives me?
It allows your Beholder to move from cover to cover, while still firing all his rays. So he could be safely out of range of any fighter, paladin or barbarian, while being in cover against any ranged weapons at all times, and STILL get to attack. No matter where he moves, if he passes through their line of sight even for a split second, he can use his free action to attack.
Regarding the tumble skill:
[TABLE="class: grid, width: 500, align: left"] [TR] [TD]
Tumble DC[/TD] [TD]
Task[/TD] [/TR] [TR] [TD]15[/TD] [TD]Treat a fall as if it were 10 feet shorter than it really is when determining damage.[/TD] [/TR] [TR] [TD]15[/TD] [TD]Tumble at one-half speed as part of normal movement, provoking no
attacks of opportunity while doing so. Failure means you provoke
attacks of opportunity normally. Check separately for each opponent you move past, in the order in which you pass them (player’s choice of order in case of a tie). Each additional enemy after the first adds +2 to the Tumble
DC.[/TD] [/TR] [TR] [TD]25[/TD] [TD]Tumble at one-half speed through an area occupied by an enemy (over, under, or around the opponent) as part of normal movement, provoking no
attacks of opportunity while doing so. Failure means you stop before entering the enemy-occupied area and provoke an
attack of opportunity from that enemy. Check separately for each opponent. Each additional enemy after the first adds +2 to the Tumble
DC.[/TD] [/TR] [TR] [TD]30[/TD] [TD]Treat a fall as if it were 20 feet shorter when determining damage.[/TD] [/TR] [TR] [TD]35[/TD] [TD]Free stand.[/TD] [/TR] [TR] [TD]45[/TD] [TD]Treat a fall as if it were 30 feet shorter when determining damage.[/TD] [/TR] [TR] [TD]50[/TD] [TD]Climb vertical surface.[/TD] [/TR] [TR] [TD]60[/TD] [TD]Treat a fall as if it were 40 feet shorter when determining damage.[/TD] [/TR] [TR] [TD]100[/TD] [TD]Ignore falling damage.[/TD] [/TR] [/TABLE]