Can anyone offer help on the following please:

1. Defence

Which player is it best to control after aligning your defence?  I think I'm suffering from hitting the button to select a player too much and as a result end up creating gaps as it doesn't go to the one I'm expecting and I end up running the wrong way (though I love the way the computer AI is quick to notice and take advantage of this!).  Is it best to let the computer manually defend and just play as a sweeper maybe?

2. Turnovers

I get these almost as soon as I go wide - any tips?

3. R3

I have never once managed to get away with this (hands in the ruck) - does anyone have any tips on when to press it?

Any help really would be appreciated, thanks!