Jim I have friend that has a large Tepee and I will contact him on the kind of poles he uses and get back to you. He stayed in his tepee all Muzzle loading season. I was looking around for a picture of it. He is set up on a Island in the Eau Clair river. I helped him set up a Franklin type of stove in it. Burning a open fire in the Tepee got a little too smokey for him. We went double pipe where the pipe exited the smoke hole.
My thoughts on the type of poles depend on whether you son is going to be moving a lot or just in one place. If he is going to be moving he would want light strong poles. Then these kinds of woods Aspen, Basswood, White Spruce, White pine. My perferred would be White Spruce. Each has there advantages and disadvantages. Easy to find and straight would be Aspen and White Spruce where I live.
If his Tepee isn't going to moved much Maple will do, although they will be heavy and his Squaw will complain ( I don't know if he wants to listen to that or not ) Hee hee As far as to cut now or later for the bark coming off. Either way maple bark isn't as easy as Aspen. If you cut it now less or no sap in the wood will dry faster. Also less splitting of the wood as it drys. One thing you might consider is girdling the tree now and cutting later. A shaving horse and a draw shave is the way to go. With out that,
poles on some saw horses and a place to fasten one end. I would not worry about getting every little piece of bark off just around the limbs and one slice in the none limb sections. When the poles dry the bark will fall off.
I will get back too you on what my friend uses. Pete