Doug, I've got one of those kits cut by The Aeroplane Works. I'm curious as to what engine you'll be using? I want to go with gas but I have reservations about how easily I'll be able to hide it with a dummy radial.
As for the shear webbing, it wouldn't hurt but is probably unnecessary.
Although, as I recall, it's only sheeted from the spar forward (like in D-tube construction) and not fully sheeted like the TF Mustang and similar planes, the fact that it's a bipe means that twisting will be resisted with all the cabanes and N struts tied together.
I really don't think shear webs resist twisting as much as they resist up and down flexing anyway...Not sure about that though.