It is normal to set an expiry date on the unissued bookings so that they can be released back into the system. Perhaps if you know the date that you are going to start at then you could nail that it and then open date the rest of the tickets whilst you get yourself sorted out. If you do not know your route, don't hold the seats as I might need them when I do know what I am doing!

Inventory management can get mighty fed up of holding off seats when there are better ways of using that inventory. They might just cancel your whole booking to get hold of one seat for a 1W emerald who is going somewhere on only one of your sectors.