endless nerd rant as I go through the update
Sakuya can actually do POW-murder-based builds pretty well for status knife strategy in random battles, although it's definitely slightly unorthodox- it's nice whenever you don't want to use materials for a 2-hand sword and have a nice status knife around like charm or petrification to go with the instant death. (But yeah for the most part holy crud those 2-hand swords kick butt.)
Patchouli's PATK tree is nice because the bonus is -massive- early in the game. She's incredibly effective smashing things in the face with melee weapons until about halfway through the game, and at game start it's very useful for no-mp-cost heavy damage random clearing where spamming magic is still too expensive and you can't learn MP regen pow skills. Book's selling points are AoE physical skills for melee patch, or Reading to regain mp. But yes, it's one of the less exciting specialty weapons. (Even end-postgame there's actually still a few cases where elemental weapons can be as good or slightly better than her magic for some bosses, if you want to be goofy. But it mostly falls off once magic spamming is affordable, unless you happen to have the slayer dagger for that one boss...)
Also, with Aya commander, +10% casting speed is actually pretty good. Speed stats don't vary wildly too much and there's often a fairly low difference between what'll let you go before or after an enemy... even a few points of speed make a difference if it means getting one point over the enemy. (Although, of course, -all- of the commander passives are indeed fairly small effects.) Her 3-bomb Paparazzi is amazing, though, oh man. A real lifesaver... or just convenient for Yukkuri smashing.
When it comes to Exorcism and Divine Barrier, as I understand it, if the enemy has 10 Divine Barrier, 10 exorcism will completely negate it. I'm not entirely positive though because there's not actually many cases to test where you -have- exorcism and a relevant enemy (and you don't already have 100 exorcism...)
Phoenix Skydance (why did they not translate hinotori to phoenix? same with her special craft item, hinotori feather.) is a polarizing formation. :T The baiting is REALLLY powerful (unlike Hakurei's weak bait) but the def loss is similarly massive, so the wrong people getting hit is lethal. Very effective, but can be risky.
Synthesis get! "Sometimes skip a tier" yeahh, that's one way to put it. Much of the equipment doesn't make enough of a difference to be worth the valuable materials they cost (especially in the first half of the game, most of the character weapons are hardly better than the generic stuff- and later they cost hefty amounts), but sometimes it really is a big help to craft a couple character weapons that you're about to get hella use out of.
The vending machine weapons are a big step up at this point where the Patk values are just plain better than what you have, so if you want the codes, here ya go.
68997264 : Melon Sword (Exp earned UP)
16394122 : Gamer Japanese Fan (Item drop rate up)
28896765 : Animate Pen (Ignores defense(small))
75024087 : White Lance (Power earned UP)
71228829 : Akiba Cherry Blossom (HP Drain 10%, MP Drain 1%)
98530865 : Messe Dagger (HP&MP+10%)
28614360 : Tiger Axe (Ability to use 主砲, Main Cannon)
30723811 : D-Staff (one-handed staff, so you can use a shield)
...a few in particular are worth using later in the game, too. The postgame upgrade for the Akiba Cherry Blossom is -sweet- for mp drain, and Melon Sword still works on your commander for exp. Dunno quite how the Power Up functions though...
