I will give you my thoughts and they are just that and probably will not answer any of your questions, but, I am sure that someone more knowledgeable than me, will chime in soon.
1. A Furled Leader made from, lets say 2 pound test mono, can be fished just like a thread leader. The thread leader will be more limber than the mono. A thread leader needs to be allowed to dry out before storing in a case so that it will not mildew. I have made Furled leaders from Coats & Clarke 100% Nylon Quilting thread and feel they work identical to Thread leaders and are limp like thread. Mono leaders may have more stretch then thread.
2. I feel the length of a Furled Leader is just a personal thing. I use a 6' Furled Leader on my 4wt, 5wt, 6wt and 3 wt. These rods are all either 8' 6" or 9' in length. I do have one 5wt in 8' length that I am going to make up a 5' Furled leader for because I usually use at least 5' of tippet and on the 8' rod, I have to bring the Furled leader into the tip top when landing a fish and feel a 5' leader would allow me to keep the leader out of the rod tip. On my 7wt for smallmouth bass fishing, I intend to try a 4' Furled leader and only about 4' of tippet because I make my Furled Leaders from Berkley Vanish Tranistion which really sinks quickly and turns my floating fly line into a mini sink tip.
3. Since I do not use the small round metal rings on my Furled Leaders, I cannot respond to this question with any negative or positive responses. I use a Shorb Loop on the butt end and the tippet end and do not see any problems with changing tippet. I always put a perfection loop in the end of my tippet and attach it to the tippet end of my Furled leader with a loop-to-loop connection and I have no problems with changing out my tippet.
Hopefully, some of the above helps......
Keep in mind that your questions are like a lot of questions that will draw many different opinions because each fly fisherman fishes different from the other. Some only use very small dry flies and require a different furled leader for their style and some, like me, only fish streamers, buggers, wet flies and nymphs and my choice of a furled leader will be different. I guess you will have to sort through the responses and pick out the answers that fit your style of fly fishing.
Last edited by WarrenP; 03-25-2013 at 04:13 AM.
Fly fishing and fly tying are two things that I do, and when I am doing them, they are the only 2 things I think about. They clear my mind.