I would do this as well, but the long flat glide is not your critical condition. WHat you want to do is make the canard adjustable - use a straw or dowel as an axle. The critical aspect on a plane like this is uncontrollable pitch-up. When you get the elevator/canard control past a certain point, the plane will continue pitching up until it is inverted, if the CG is too far aft. It would either flip over at takeoff and slide down the runway tail first, or pull-off a figure 9 when on approach.

The problem is, it will fly just fine when trimmed for level flight. So, you need to check the CG for slow flight characteristics. Set the canard for 20 deg pitch up. Adjust the CG so that when you gently toss it the nose hangs up high while the glider flies slowly but maybe not so efficiently. THis will ensure that the plane will remain controllable at low speed.

As for using the rear fuselage strakes for control, the shape of the surface will not allow very much control power at all. You should keep it simple and use the canard for pitch control.