Lots of good questions that might demand an entirely different forum :-) LOL
First of all, I'd say remember it really is fly-fishing. It's not dapping as some might think. You really are casting a long line, unfolding a leader, and making a delicate presentation. It doesn't get much better.
I discovered it primarily as a backpacking alternative. I'm constantly looking for new ways to simplify and lighten my backcountry experiences. When I saw this, I thought it at least deserved a look-see. I now relish the opportunities to visit high country (Sierra mountains) streams with nothing more than a rod, a line, and a handful of flies.
Understand though, there are limitations--it just depends on what you want to accomplish. For example, if I were to head up to the Yuba River or Lower Sacramento River here in NorCal, there's no way I'd use Tenkara. Those football sized rainbow pigs would destroy the delicate tips of my Tenkara rods. They'll put a serious hurt on a 6wt! However, to sneak up on a California Golden, or brookie, or find an elusive Goose Lakes Redband trout, it's the perfect choice :-) Matter of fact, this last year I went after the California Heritage Trout Challenge -- catching and releasing six of California's native trout in their heritage waters -- and I did it (my second time), all Tenkara.
FWIW, I own two Tenkara rods -- the 12ft 6:4 Iwana and the 12ft 5:5 Ebisu. I love the lightness and backbone of the Iwana. I love the delicate "slowness" of the Ebisu. Fishing for little 6-inch redbands calls for the Ebisu. Fishing for some wild Kern River rainbows takes all of the Iwana. You'll just have to figure out where you're going to be fishing and what the fish are like to determine the rod.
That said, I'm a total convert when it comes to furled leaders. I use 'em on everything. I started furling my own using a pattern developed by Kathy Scott. And this is yet another forum :-) Ha! I've made 'em out of mono, fluoro, and Danville flymaster thread. My favorite so far are the fluoro. Although, I just picked up a bunch of new Danville thread to try some new formulas. Drop me a PM and we can discuss the finer points of furled leaders for Tenkara.
I'm just glad there's an interest, that people have open minds, and that we continue to learn that fly-fishing (regardless of "style") is an amazing and certainly, most enjoyable, pursuit.
Whoa, did I go way overboard...