A couple more things Bill. Bass is fine for a motor block, but you need to loosen the mounting bolts after every flying session or the wood will compress while it sits. Then tightening the mounting bolts will torque the case. The boom should go almost to the front of the block and have the bolts go through it- a .113 or so numbered bit will just clear 4-40 bolts. But since it has a metric engine and mounts, use 3mm bolts in a slightly bigger hole. Most Euro F2D planes use pieces of 1.5mm(,062in) fiberglass plate epoxied top and bottom back to the spars. The motor block really need to be made very precisely, especially parallel top and bottom so the beams don't torque the mounting tabs on the motor. Ball bearing motors particularly don't like to have the case twisted.
To fix the motor mounting bolt probem you can use Dubro brass inserts. They screw into the right sized holes and use some epoxy on them. It needs 4 short bolts though. Or you can cut some 3/16in. aluminum wire, cut the wire to length, and drill a through hole and tap it into place with some epoxy. Sand the ends flat and parallel with the block.
The original designs like this(Steve Hill's Arrowplane) used a piece of hardwood dowel pressed lightly and epoxied into the front of the boom and extending far enough back that a through bolt could be used to mount the bellcrank directly on top of the boom. Another way would be to cut a strip of 1/32in. aluminum. Half wrap it around the boom with the ends to the left. Bend the ends to into a zig-zag shape that will take the bellcrank and pushrod and attach with a short 6-32 bolt. Hold the mount in place by figure eight wrapping some carbon tow around the aluminum and the boom and then soak it with thin epoxy before installing the bellcrank. Or you can run a piece of 3/32 aluminum welding rod through the BC mount and boom and afix with a bit olf epoxy.
1/8 x 3/8 bass, spruce, or pine is fine for spars, although a bit heavy. For flat spars you need to add a doubler laid flat in front of the spars about 1.5in. long and tapered back to the main spar. Either that or cut quarter inch deep slot in the block under the spars for vertical doublers to lock the spars in place. You need at least a 3/4in. square of gluing area to hold spars to the motor block.
Anyway, the planes you are putting together should fly just fine. Just some tips to make them more durable.
Dacron fishing line won't do much for holding the wing together in a crash. It's too stretchy. Needs to be carbon fiber, Kevlar, or possibly Spectra fishing line, but that is hard to glue.