I booked a star rtw off the website , which is booked by lufthansa (even if you don't have a lufthansa sector)...
They were able to give me rebooking quotes (tax adjustemnts) by email within a day of my inquiries, and rebook immediately when I phoned them. They would just email the ticket along.
however, they did say they wanted 2 days notice for changes, so you might still run into trouble if you are trying to use it as a very flexible ticket.

Still, for the money (ability to reroute for $125 fee) it's really quite a deal.

Shawn