Team A are on the attack.

On the last tackle a player from team A, circa 35 metres out, kicks the ball high up in the air and it goes over the dead ball line on the full.

How would the game be restarted?

Thanking you.

20 metre optional kick (20metre restart) to the defending side. Basically the ball has gone dead in goal so whether it bounces or not is not relevant.

Tap 20.

A player plays the ball after a tackle can the acting half kick it from the floor or does he have to pick it up?

If he can kick it, it's answered
if not
how does it restart and what would the penalty be?

Then why at the game I was at yesterday did the referee give a turnover from where the ball was kicked from?

5th tackle maybe?

I did say it was the 5th tackle. Ridiculous decision.

Either way, should have been tap 20.

Yeah you can kick it and play on.

I had a question about rules, so might as well post in here while you're all helpful

At what point after the tackle can the defenders start to advance? This year I've seen referees calling it differently, but if the defence are back 10 with the ref can they only start to advance once the player playing the ball has touched it with their foot or is it as soon as they are on their feet and start to attempt the play the ball?

Some referees I've watched seem to want to wait until the ball has been played at with the foot and is in the acting half's hands and call offside for moving early, others generally only blow for players that didn't bother getting back 10 at all and seem to let play continue if defenders start to run as the player bends to play the ball.

The rule book on the RFL site states only when the ball is clear of the ruck, but I haven't seen any team this season waiting for the ball to be passed or for the dummy half to start running to advance forward.

Restarting play at 20m – with an optional kick (i.e. any type of kick) 2. The game is restarted with an optional kick from the  centre of the 20m line if:
(a) an attacking player last touches the ball before it goes out of play over the dead ball line or into touch in-goal except from a penalty kick (see Law 3), or from a kick off from the centre of the halfway line. (see 4(g) and 6(b) below).

An attacking player has kicked the ball over the dead ball line. It doesn't have to bounce in field. Tap 20.

I suspect he has gotten confused with kicking it over the touch line on the full, which would be a scrum from where the ball was kicked.

The ball is deamed to have cleared the ruck once the ball has been played not when it has been passed by the acting half

Once the tackled player touches the ball with the foot, the ball is in play.