Beautiful runner, well done.
A satin binding cut on the grain of the fabric (not bias) would look good and help stabilize your edges.
Suggestion for next time - try cotton upholstery velvet, which is much easier to work with. It does not stretch, is a bit heavier, and washes nicely too. We have been using it as table draping for shows for about a year and a half. Still looks new (except the one wax and glaze got dripped on).
