Afraid not, it is only what is on at that current time.
Movies is the only section that allows you to watch from the start.
See below which confirms features on Now TV
Agreed as regards Sport, but regarding rewinding Entertainment, the link you gave doesn’t quite bear out what you said:-
You can pause and rewind the live TV channels for up to 30 minutes with any of the NOW TV devices below:
On all other devices, you can only pause or rewind on demand movies and shows.