1) Almost all tank busters are physical not magical
2) Warriors do more dps than a drk, MT or OT. As an MT they lose 25% from stance, gain 20% from maim (-5% total) which is the same as the DRK (-20% from grit + 15 from darkside), however, Warriors can debuff the enemy (can be shared, sure) berserk , infuriate (meaning they go from -5% to +20% or then stack cds at this point for mega damage).

As an OT, not even a comparison is it? Deliverance is auto 5%, maim is 20%, stacks give crit chance. You can spam dark arts /soul siphon and run into mana issues after 3-4 rotations, which has its own issues.

3) Reprisal stinks. Cant apply as an OT. No real control as an MT. Has gaps in its uptime.
4) -10% int buff is probably the least useful damage debuff. It helps--sure, but nothing like storms path or rage of halone.