Check out HowToBrew.com and look at "Appendix D". You'll find that the wort entering your tube near the crimped end would have to travel the entire length, while wort entering futher down the line would travel much less, possibly lowering your efficiency.
The copper isn't bad to work with, and most of it should be left unsoldered anyway so you can clean it out.
I was able to build mine so that the outside lines pressed against the sides nice and snug to prevent it from wiggling. Then I used "t's" to run 3 parallel lines down the middle. And use 1/2' copper, not 1".
A fool and his money are soon partying.