Re: tenkara questions
I agree with the experienced voices above, but would add:
1. You'll find you need to adjust length less than you'd think. Tenkara rods can fish very compactly on small brushy streams, with a naturally compact casting motion and a much easier bow and arrow casts then western rods. I fish some very tight creeks with my 11-foot and don't fish my 9 footer anymore at all.
2. Snipping a fluorocarbon line down to size is the most common adjustment I make.
3. I have fished a partially collapsed rod and it does fine for a temporary adjustment, and frankly I get away with not even worrying about grip or loose sections for the small fish I am usually targeting when I do this. You can also just take the grip section or two off the rod and fish without a grip if you find yourself over-rodded; this works better than partially collapsing if you need to adapt for more than a cast or two.
Bottom line though is you'll cast a longer rod more easily than you think, and after you get used to it you will appreciated the added length.