Search this site for "sweep" -- there's lots of discussion about the ideal amount of wing sweep, and flap sweep, and why.

I'll never be one to pick on someon's design. 

Does look like it did a figure "9" though.

You have to kind of close your eyes to the chest-beating, and pay attention to who's saying what.

The consensus, such as it is, seems to be that a swept flap hinge line -- fore or aft -- makes for worse performance in the wind.  Ditto untapered wings.  The combination of tapered wings and straight flap hinge line makes for the wings we see.

The unswept hinge line notion is not universal -- you'll see some good fliers who insist that it's no problem, or is even beneficial -- but you'll also note that most Nat's winners don't have hugely swept hinge lines.

If you pay attention, you'll notice that there's a lot of chest-beating over why one wants or doesn't want swept this or that -- but the airplanes that actually win contests tend to have some mighty similar features.

If I name names I'll just hurt feelings.  I look at whose one at the Worlds and at the US Nationals, and if I can tell who's top dog in their country if it's outside of the US.  I look at the people who's statements seem to be consistent and well thought out across the board, and who don't seem to feel a need to engage in pissing contests.  Finally, I tend to give more weight to things said by pilots and engineers in aviation-related specialties, when I know what people do to pay for their modeling supplies.

My day job is a circuit and software engineer for products, and engineering discussions can seem pretty cruel to an outsider (we're critical with each other with reason: mistakes are expensive, and having to justify every detail of your design makes your design better).  You can't last long on a design team if you can't distinguish between a perfectly valid and acceptable, if harsh, critique of a potentially bad idea and a personal attack.  So I'm probably unusually prone to view discussions that get very critical in a more positive light, as pointing out more issues that need to be considered, rather than as personal attacks.

Look up "rolling moment due to sideslip" and "yawing moment due to sideslip" .  I think you'll see that you're on the right track, but might consider a taller vertical stabilizer. 

Reynolds number shouldn't matter. 

The dMECO Sportwing was among the designs I'd hoped to attract when I began the VSC back in '89.  Jim Thomerson did enter and fly one, which was great to see.

However, with a few notable exceptions (thanks, guys...you know who I mean), OTS appears to have become "the Jamison/Humongous event".

Not at all what we had in mind.

You have to blame the "Jamison/Humongous" craze on the kit manufacturers.  They make it easy to produce yet another example.  Maybe flyers will get plenty tired of seeing these and branch out into something more interesting?

Floyd