With the ice giant I would strongly suggest going for a proper metal frame and possibly mounting four large engines instead of six small ones. For the metal frame we need to talk about what the plane is doing outside of increasing our TC. Which is dropping armored vehicles and artillery for our paratroopers to use. You can make a huge-ass wooden plane but, by it's very nature it going to be slow as wood can't handle high speeds and, it also going to be much weaker then metal if the plane is hit with flak rounds. As long as we don't hit NE the price of the plane isn't going to affect it's TC so we should make a plane that doesn't fall out of the sky when sneezed on and is faster. The total cost of the plane would need to be over 14(aka 7 ore, 7 oil) to make it NE. For the engines making them bigger rather then using more would help any other aircraft we make. After all during this period it's a race to see who can make a proper full size jet engine.
Whilst I agree with you about the engines, the wooden frame I will defend. Transport aircraft in WWII were made of wood on multiple occasions, even ones designed to land in hostile territory. It isn't meant to enter combat; the size and speed means that if it does, it isn't going to survive no matter what it's made of. As for flak, hopefully our experience with the Reckless will let us build a plane that can still fly with a few holes in it.
For TC purposes, yes, it could be VE and still work. But if we want to launch serious airborne invasions, we need to be able to deliver lots of men and materiel quickly, which means having lots of transport aircraft. I'd really like for these to be merely Expensive.
Besides, it's not all wood. We will still use aluminium where necessary.
The engines, though, I would rather be regular piston-engine propellers. Whilst turboprops are a lot more efficient than turbojets, I don't believe they are as efficient as piston engines (in this time period). Also, it may add difficulty to the design.