Personally I'm into a lot of music from classical over jazz to metal, though I mostly listen to prog bands like Symphony X, DT or Spock's Beard. If I want it groovy some stoner rock, death n' roll (Entombed, Revolver) or older Tampa-Death like Obituary and a lot of other stuff.
I consider your musical intention more death/blackish, but I don't like too much music style classifications.
Ok, I listened to the master's thing. The production is better, there were more microphones I think, for the guitar sounds like a guitar this time.
Have you ever tried (if possible) recording not live but one after another with a computer or multitracker? That would make it possible to play some bass on it, which is missing in the song. Of course, you could try to add more bass to the guitars to have the whole frequency spectrum covered, but a bassy guitar isn't a proper substitude for a real bass.
About the guitar EQing: Good question, this always depends on the guitar, the amp, recording environment and a lot of other things, so I can't say a lot about that. Normally the guitar dominates the mids in the spectrum, but again this depends on your taste. Expirimenting is the best help.
Anyway, I don't know the original song from Opeth but your version is cool.
Still the bassdrum isn't always in time, which just kills the good groove.
Practicing with a metronome once in a while can be of good help to improve that.
Keep it up,
Kosh