Agree to the last post:
As soon as you have a reservation you are protected. The ticket itself has not to be dated.
So the best strategy for me is:
- open date all coupons in the ticket
- have the ticket issued in first class (even if there is no F on a specific sector because then it is easier to change - assuming you get an F ticket)

- Have my TA book all the flights (not necessarily in one single reservation).
- email or call the TA when i need to make changes to the reservation.