wing loading is 1.5 lbs * 16 oz. per lb / (281.25 in^2 / 144 in^2 per ft^2) = ~ 12 oz/ft^2

This seems a little hefty for a glider that size. Particularly where I think reflexed airfoils on flying wings tend to get less lift per area those than on a regular wing (is that right?)

this page has way too much detail on airfoil and CG for flying wings: http://www.mh-aerotools.de/airfoils/flywing1.htm You might sanity check by finding the cg for a similar shaped model.