HI Paul,
Yes the carbon tube does go into the aluminum one to strengthen it. It will fit but takes a little working. I first sanded inside edges of both ends of the Aluminum tube and then lightly landed the full outside of the carbon tube with some 400 grit wet sandpaper. That did the trick for me. Then I used some Z-poxy finishing resin thinned a bit to mate the two together.
As for the turbine, my Viper has full smoke and also electric gear and brakes which put the weight right at 36 with a full UAT. I am using a 36 lb Rhino and find it to be a really good match, even with full fuel and smoke oil load