How do CO Units move? Straight ahead and then they can turn at the end of the move, or can they wheel as they advance? 

CO units may wheel during the movement. Just place the stick so one end is on the central figure in the unit, angle it as you want, then place a finger where along the stick you want the unit to go and slide the unit until it meets your finger. 

What does it mean that OO units must Always recoil at the end of a melee? Do they recoil even if they win? If they lose and their enemy follows up, do them recoil again?

At the end of a clash (that is, after a combat die roll exchange, or multiple die rolls if the first one was a tie and the melee had to go on) between a CO and an OO unit, the OO unit must recoil 1 x Short EVEN IF they won. Exception: they do not recoil if they completely destroy their enemy unit. See Ogam, p.18.

The CO unit, if they can, may choose to follow up the OO unit but the follow up does not cause any other recoil this turn.

In a clash between a CO and an OO unit in which no on is destroyed, at the end of the clash both units recoil 1 x Short. The OO one recoils becuse it clashed with a CO unit, and the CO unit recoils because it lost a melee. This happens quite rarely.

If a Dashing unit wins a melee and follows up, does the second impact generate an additional attack action? 

No it doesn't.

Do the effects of a tie apply to a Free Hack? Should the combat be rerolled as per a regular melee? And in the case of a tied free hack between gods, does the Clash of the Titans rule apply? 

A tied free hack (including one between gods) means that nothing happened and no effect applies, not even the clash of the titans rule. It just means that the god that suffered a free hack was not hit. In other words, a free hack has game effects only IF the unit performing the free hack wins the free hack roll. Any other result is a no effect.

Is there a draft of tournament rules?

We are working on it as the first official tournament happens in Rome on November 30th. Keep watching this blog.