Ethan, tele has been the best thing I've done for my skiing in over 40 years. Other than Telemarkdown, there are also a few shops near Killington. The Platty rental shop also actually has a decent selection of used tele gear to give you a feel before investing in your own setup.
Your more detailed questions beg more detailed answers. You can definitely carve tele turns...a more robust or "active" binding helps in that regard. IMHO, if you're going to go 75mm, you would be happier with a 22Designs binding...either The Vice or The Axl. (Axl has greater tourability). Again in my opinion, the increased/additional torsional rigidity afforded by NTN is clearly worth the additional price/weight. For me, NTN, is just the bomb! Total freedom. I feel confident to carve a turn pretty much anywhere, in any condition, while affording me the freedom I desired to take my skiing to the next level.
I've been teleskiing for about 4 seasons now and it's all I do. I don't even own a pair of skis with alpine bindings anymore. I caught the bug quickly.
Watch his skis and the tracks through the turn. You put a lot more weight on your inside/uphill ski with Tele, and active bindings force you to do this - as you push the tongue of the boot forward, springs in the binding put pressure on the tip of the ski.
Tele is really weird if you've only ever Alpine turned. Alpine is all focused on inside edges - think starting in a wedge and progressing to parallel turns. Even then, outside edging is under very light load. Tele you put a lot of load on that outside edge and what it feels like is the turn actually happens on it. Ideally you are skiing on both skis but your Alpine brain thinks you are putting a hell of a lot of weight on that ski to make it happen right.
There's an old Alpine turn, called the open turn, which relies on this method. Actually if you watch XC racers when they do step turns they do this in a way. They push off the outside/dh ski and turn on the inside ski (outside edge). You can do this on Alpine skis too, but it's a weird technique. Tele is an Alpine turn + an open turn with an offset stance. There's a lot going on.