A very wise policy.
As to AIS and Radar, we have both. You get much better chances of a response if you hail a ship by name. We have both transmit and receive and we were hailed one time by name going down to the Caribbean (via Bahamas). It was another sailing boat looking to chat during an evening watch.
For watches. It's just my wife and I. We do 2 hour watches from 4pm to 8am. If we can go longer, we do and if we can't do a full 2 hour shift we switch early. When either of us is even 1% unsure of a situation, we are both on deck until it is resolved. Fortunately we both have many years of experience, so this doesn't happen all that often.