Two comments for thought:
1. Yes, etickets may offer more convenience for changes, but sacrificing segments is a big price to pay. If you are reasonably close to a ticketing facility, why such an aversion to paper? Occassionaly the alliance member's computer systems don't talk to each other all that well. More than once I have shown up at the airport to check in with my record nowhere to be found. Having the paper ticket basically saved me, as the reaction was, "if you have a valid ticket, we have to let you on the flite"
2. Open dates work well for many and give greatest flexibility. However there are drawbacks a) if open you will not be protected if routings or schedules change. This may mean reconfiguring the ticket if schedule changes are extreme. If the segment is confirmed, the airline will get you there without the necessity to use additional segments, etc. b) Importantly, if open the appropriate fare bucket must be available for the dates/times you want to fly. Often not a problem, but capacity controls on these flites can be tight on popular routes in season. Thus, some lead time and flexibility would be required, especially if wanting to confirm shortly before departure. Thus, my inclination is to start with something reasonable and confirmed and then change dates as necessary. Obviously others may be more comfortable with the risk and uncertainity inherent in a open ticket.

Just some points to consider. Obviously both choices are possible and common.

Sounds like a great trip.

Rens