Being a simple guy, should I be writing the company ops manual I would suggest.
AP must be used for all departures and arrivals ;
1. LNAV proceedures (eg, schipol SID/STAR's)
2. Night
3. IMC
4. Cat II or III ILS
5. Any other time that EITHER member of the crew considers nessecary.
If you want to practise your hand flying skill, thats a good thing, but safety should always come first.
cheers
Bateman