If you have a flourescent fixture that your converting from direct wired to plug in, do you need to add a fuse somewhere in line for any reason that I'm completely missing at this point in time?
No. The only "fuse" that would normally be used with that fixture would be the one the household circuit connected to in your homes distribution box. More than likely, a circuit breaker in that case. If your cabinet is properly wired, that same breaker would protect the whole cabinet , and anything else on that circuit. When I say "properly wired", I mean proper connections, good insulation, a junction box and wire gauges appropriate for the loads they are intended to carry. If in doubt, leave the plugs on your components and plug them all into into properly designed and industry approved, breaker protected power strips.
Also keep in mind that fuses and breakers are only useful for protection against direct short circuits and overloading. I've had one very scary situation in one of my previous homes with a commercial Bunn coffee maker. The plug was old and apparently in bad enough shape for the AC to arc between the prongs. It wasn't enough of a short to trip a breaker / fuse, so it just arced and burned everything in-between. Fortunately, I was right there when the smoke and fire started and yanked the cord (leaving one the charred prongs in the outlet.
A little off topic, but it illustrates why fuses can't be relied upon to always "save the day". They only protect against one specific type of issue. The best protection is knowing what you are doing and using safe and accepted practices, especially when handling AC line current.