Bomb Destroy can only be applied to an enhanced trap. For example, Spear Trap + Cut Parts then Bomb Destroy can be added, but you can not apply Bomb Destroy to just a Spear Trap.
For reference: Rank 4 did 2000 damage, while rank 5 did 2500 damage while using the same weapon.
This damage of this ability is significantly affected by skill rank, your condition, and your physical attack.
It may be possible that DEX has an extremely small contribution to damage, please see comments for test data and more details. There is no known evidence at this time that STR has any effect on Bomb Destroy damage.