To solve the problem of braid spinning on the spool, wrap the line across the spool one time. Take a piece of electrical tape about square, and put it across the line, using your fingernail to make sure it contacts the spool between the line wraps. When you wind over the tape, take some time and make sure the first few wraps are tight. I've always done this and never had a slip.
For knots I use the Palomar.
I haven't had much luck with Fluoro's on spinning gear because it seems stiff and prone to retain to much memory.
Like all lines, Fluorocarbon should fill a need. If you need a line that is abrasion resistant, has little stretch compared to mono and sinks rapidly, it can't be beat. If you need a thin line that is abrasion resistant but has some stretch, then something like P-Line CX works well. The list goes on.