Thanks for all the input! Lemme try to respond to everything in order...
-I've definitely noticed the lack of piercing damage when it's come time to fight stuff like Blackenmels/Helbelmares... Oddly enough, Ran can pierce their defenses a little with her laser, though not for much damage yet. Other than that I've had to resort to nukes like the Megawatt Kill Everything Gun (or Silent Selene as mentioned). (Then again, by now since I'm just breaking into 16F enemies are surviving more turns anyway, though that might just be me not spending enough time on the floor below.)
-I...hadn't even really paid much attention to how little I've got in the way of magic, especially with two of the three being MYS primarily(Though Reisen's Discarder's not exactly worthless, if I needed a FIR single target magic attack I'm probably better off with Alice and Return Inanimateness since it's almost nuke-level IIRC...) I'm also considering using Yuyuko, but it'll probably be a while before she's got the SP to attack often enough and I don't recall if she's got the MAG(Especially if I was going for a MND build originally) to deal the damage I'd need for when her high DTH rates aren't an option/fail.
-Continuing from above, yeah, I've now noticed the severe slant towards physical damage. For SPI physicals, I do have ATK-Komachi, so there's that. (Plus Narrow Confines and Ferriage provide multitarget DTH chance for randoms which is nice.) Should I bring Suwako along for randoms more for Iron Rings, to get a MYS attack in as well? (I've got Youmu able to fire off a couple Cherry Blossom attacks now without needing to stop, so I don't know if I'd need Croaking Frog as much)
-I'm noticing Sakuya's diminishing returns already, and really have been since like 13F. I wanted to try to use her, to prove to myself she could be viable, but her ATK just isn't high enough to make her attacks worth using, though I have liked Lunar Clock quite a bit. Only a matter of time before she gets axed, I feel.
-Yeah, the Linear Gun is insane. It's typically my strongest attack on offer unless an enemy has much higher DEF than MND. Nitori's also not all that slow, AND her nuke isn't mega costly either, especially for its outrageous power. I wouldn't consider it unfair if they'd made its SP cost DOUBLE, to be honest, though she then wouldn't be nearly as useful earlier on. Speaking of Nitori, her Waterfall attack is actually quite nice for not-high-DEF enemies. Currently seeing like 15-20k on most things without high DEF stats.
-I use Ran for her magic in randoms, and for her buffs usually in bosses. She's got the SP to fire off 3, almost 4 of her buff spells without rest now.
-Being on 15/16F, I've already seen Thousand Hand Kannon and Rasetsu Fist(The latter being the only move Hill Gigas got to use (Poor Reimu, getting punched to death instantly) before I just mowed it down with PAR, but that's besides the point.). Yeah, Tenshi can't do jack about those, I'm well aware. Her HP's not BAD right now, just not good enough to stand up to those. Might need to remember to switch in the shinigami when I know an enemy can use those sorts of things.
-Biggest reason I won't worry about Kanako is she's WAY far into the future and thus not of my concern yet.
-I've heard great things of Soaring En No Ozuno or whatever, and I intend to see if it's as great as people say eventually, though as of current I've yet to see it as impressive, I'll guess it's like Moonlight Ray/Demarcation in that it gets better and better scaling.
Anyway, thanks all again for the input!