BMatthews

The sweep of a wing is set by the line of the 25% chord line. In this case it'll have a tiny bit of sweep forward.

I'm not sure that I agree with longdan's logic. Swept forward wings actually tend to avoid the spanwise flow to some extent while swept back wings (which a straight trailing edge and tapered back leading edge would give) tend to encourage spanwise flow. The whole logic behind the Schumman planform is actually to accelerate the spanwise flow at the tips so the air shoots off the rear with enough energy that it can't flow around and back onto the upper surface.

In any event the amount of sweep one way or the other is minimal in this case so I don't think it'll make a hill of beans of difference. If you like the way it looks then stick with what you have.

Probably a more important issue is the upper surface sheeting. It doesn't seem like it's extended back far enough as per Mark Drela's specs as laid out in the write up on the Allegro Lite. The idea is that it's critical to not have a sharp transition near the high point of the airfoil. And a sheeting to covering transition at that point will always have a bad sharp point between each rib.

I don't know what you're using for a boom but it needs to be quite stiff but able to flex a LOT. Discus launches generate HUGE amounts of bending in the boom and I can't see any sort of wooden one holding up if you're using it as a thin boom.