The Golf R is a great car, and the MK7 can be tuned into the 11s with simple bolt ons (intake, tune, downpipe and DSG software). They handle on par with an STI, with a bit more tendency to understeer at the limit because haldex AWD. For the majority of people wanting a sporty car, they'd be absolutely SHOCKED at how fast a Golf R can be on back roads if they actually drove one. And if you mod the DSG ones, you can get well into the 11s if you wanted.
Great do it all car. If I had enough money for a 40k daily, I'd have a MK7 R.
The same, just aluminum. Assuming you're referencing the rear subframes.
The TT has better suspension geometry, not subframe related. It's all in the LCA and Knuckle design due to wider front end of the TT allowing for more camber (adjustable) aluminum arms and knuckle vs steel, and a knuckle that has a much better design for proper geometry.