[Paddle Shift] I tried looking in manual but dun have much info.

I wanna ask:

1) I stop the car completely before shift from D to S
Can I do this without stopping completely, i.e. still driving at say 30km/h?

2) When I press accelerator, the number is not shown until I press the paddle shift... but why count starts at 5?

3) How to use paddle shift efficiently?

For info, i have no problem driving manual car using manual gearstick

thanks