It is quite difficult to hold the listeners attention thru an entire instrumental with one type of lead instrument. Now it's been a long time since I learned the songs on Paranoid but I did like the heavy rock and cut my teeth prior to that on Clapton and Hendrix. (I had been playing guitar for over ten years when Black Sabbath released Paranoid in 1970)
The guitar work is good. I like the tapping. Since I have played drums for some 50+ years, I would use a lot more double bass work. It pretty much defines the metal drummer genre. Of course that is easy for me to say. My double pedal work is uhmm, suggestive of a 65 year old who rarely practices. Keep it up.. good stuff. Oh, you know what would be kind of cool in this to alternate the guitar lead? Pedal steel LOL, just kidding. Seriously, an overdriven B3 sound would just kill in this.