The Evil Smasher trick only changes 2 things IIRC, it adds the effect to all equipped guns, and the effect is retained even when the ES is not equipped.
Full effects, IIRC, are: Damage Up, Accuracy Up, Fire Rate Up, Clip Size Up, Projectile Velocity Up, and perhaps Recoil Down. Since all the effects are directly tied to each other, and only Clip Size is easily checked, that is how you can tell how much of a boost you have.
It's only supposed to happen occasionally when you reload the Evil Smasher, the trick just has it go into the Reload much more often, and when it starts reloading is when it checks for the boosts, and starts increasing the boost rate.
Without the trick to make the boosts work on other guns, everyone who uses the trick would likely be using the Evil Smasher itself for combat, and just using the Menu Reload to keep from messing with the boosts.
Spell card! Diamond Will ~ Unbreakable Determination!
No, there's not an orange siren mod with +Reaper skills. The only orange class mods are the Legendary Siren and Slayer of Terra mods, and neither of those give Reaper, IIRC they both only give first/second tier skills. (I haven't used or looked at the Siren Slayer of Terra mod in forever).
IIRC Fox and Binder class mods can give bonuses to Reaper though