Nice first effort!
That vinyl tube is going to save you loads of time and grief around the bottom and the pilings. Here's a little tip also- while the length of the nylon cord sticking out past the tube will act as a swivel of sorts, it also will act as a wick and pretty soon that line will saturate and fill the tubing. No mo floatline. Now that this one is done, go use the daylights out of it and keep an eye out for the barrel swivels and clips spec'd out in the cheap floatline thread here somewheres... hit the search thing and read on.
A clip other than the one you've got there is going to work nicely for you- that little finger release thing has a-hole written all over it; a definite snap ala a longline clip is smoother around the bottom and your digits. On the next line you make, squirt a good glob of silicone caulk in the end, push the barrel swivel in and wrap it with some stainless seizing wire taking care to crimp the beejeezus out of it. Finish with the shrink wrap you put over the tube before all this and you're golden.
Jay Riffe and Co are pretty proud of their floatlines and the rest of their stuff for that matter. And rightly so- it's hardcore, made- right gear from people that use it. You wanna get sober, just try to put one together to those standards and add the costs of materials, yourself, the room, the electricity, taxes and phones so people that have no clue can call and waste your time and then take the advice and go buy some other schlock piece of crap. You'll see that a hundred bones ain't even gonna cover it. I've made my own lines as well as having several of Jay's and when it matters I throw on one of his.
sven