Have I Gone Too Far?

yes there is no need to give felicia def smoke cause her weapon goes after the lowest def stat anyway

Nah, who cares about spring chrom? Felicia is clearly a primary unit of yours and heavily invested. Go for it.

YAY MEME BUILDS! ITS DEFIANTLY WORTH IT

According to the build you posted above (in the comments) I'll have to agree with amoebasgonewild that it's a useless build. You have Barb Shuriken, which inflicts Def/Res -7 on anyone within 2 spaces of the target (including the target). Then you have Seal Def, which inflict Def -7 on one specific target (the exact same target affected by Barb Shuriken). Then you have Def Smoke, which inflicts Def -7 on foes within 2 spaces of target (excluding the target, and affects the same foes affected by Barb Shuriken).

Only one de-buff will activate since they all inflict Def -7. You're essentially making an incomplete Felicia with no B or C skill.

I'd suggest re-thinking it since the de-buffs don't stack, unless it's just for memes. Even then, I don't really condone meme builds, so I can't really say anything about that.