Well, Tyranitar;s attack is considerably higher than his special attack, so if I were you I'd focus more on that. Dark Pulse (special, power 80, ac. 100) thus isn't as good for it as Crunch (physical, power 80, ac. 100). And by the way, they both have a 20% chance of making the opponent flinch.
Definately keep Earthquake (physical, power 100, ac 100).
Stone Edge (physical, power 100, ac. 80) is a little unreliable due to it's acuracy, Rock type moves are strong against ice, fire, flying and bug, olus you have a STAB advantage. It is particularly useful against bug type as they are ofter bug-flying (plus bug is super effective against you). However, there arn't really any good alternitve rock moves, unless you wanted rock slide (power 75, ac 90). If you felt it fitting, you conld swap it with Dragon Claw (physical, power 80, ac. 100), wich wouldn't super effective against much or not very effective against much and willbe much less powerful. Really, this one comes down to your battle style. I personaly hate moves that miss, so I'm just throwing this out there.
Your Surf (power 95, ac. 100)would be good against Fire, Rock, and Ground, but it's a special attack. It's super effectiveness against ground is good because it's super e against you. You might want to keep one special attack move to balence you out, but if not I would go with either Dragon claw. And if you DO want a special attack, I'd go for ice beam (power 95, ac 100, may freeze). Ice would be super e against ground, grass, flying, and dragon. It would be great for grass and groud as they are super e against you.
