[MiraclePieCo]

I can answer #2. I used 3/4" solid (not hollow tube). It's way overkill. You could hang your entire truck from a 2-foot piece of that stuff. In any system there is no sense using anything that's stronger than the weakest component. Most aftermarket steering columns have 3/4" shafts (including ididit) so if you have 3/4" on both ends why would you need anything stronger in the middle?

And yeah, it helps the clearance. My intermediate shaft clears the exhaust header by about 1/4-inch.