GeckoGuy

Splicing line every 100ft is probably a marker they use to determine how much line they have out.  This could create weak points  with more knots.  If you have a line counter reel, this is not required.  The way you set this up should be fine as long as the reel has a line counter.  You mentioned a leader, but most people just attach the wire directly to the dipsy and put a 6-10ft leader behind the dipsy.