I tried the thing about holding the button, and in my first (and only) game today I scored two very nice headed goals in a 2-0 win... The second one was especially good with Chamakh, I got a free kick out wide on the left, I got Gourcuff to take it right footed and bend it in towards the back post with top spin, Chamakh runs in and nods it in with the keeper flat-footed... looked awesome.
Hopefully this wasn't just a coincidence, I moaned about them after my last game last night then first game today score 2

.
On the issue of stamina... They need to make the consequences for constant sprinting/pressure more than just your player being able to sprint for shorter periods when they are fatigued. They should make players get cramp (and have to go off), only be able to jog at the most, not hold their position, be almost useless on the ball and weak/late in tackles.
You see players sprinting everywhere online for the whole 90 minutes, it's unrealistic.