A few quick comments:
1) On the original Kellam & FEA damage average issue. I'm happy to vote up the likes of Lucina when she needs an Aether in 4 hits usually, while I seem to recall that Elf & Random are usually more skeptical. So I'm definitely sticking by the no-accuracy average, but if you're strict enough on skill procs, I can maybe see using the accuracy-adjusted damage average. (Braves making Awakening skill procs more frequent than other FEs & all.)
2) Re Dhyer, while in MOST FEs there's a good reason to be skeptical of Killer stratz since they're often overrated, I think Awakening Hard might be an exception. Well... Awakening if you're either not in a pair-up or skill / support isn't high enough to make the pair-up attack reliable. Enemies have enough HP that two-rounding them with Silver is pretty chancy, both Killer & Silver can usually 3HKO, and Killer gives you the chance of one-rounding (and, better yet, one-rounding on the first attack to ignore the counter). I certainly found Silver generally trash and used Killers instead for Awakening. And, DL-wise, the introduction of storebought Braves at literally the last possible time makes Killers look way, way worse in the DL than Killers do in other FEs, such that they're only useful for the likes of killing frail healers like Yulie. So basically the FE with one of the best Killers in-game when solo has some of the worst Killers in the DL.
3) Re Elf on rewarding bosses that are already durable... okay, there's definitely something to old Tallychu-esque "screw super boss durability" arguments like taking the square root of their vanilla PCHP, but there are definitely times where this makes a lot of sense. Bravely Default & Grandia 3 seem obvious examples: In BD, frail enemies like normals get REALLY frail since you can Brave-blitz them for free. It's some constant amount you can chop off enemy HP which isn't relevant for tanky bosses but makes frail ones die extra-fast. Something similar for unloading G3 Orbs on bosses or arguably similar one-shots in other games. Heck, you can even throw non-one shots that you can nevertheless have charged up beforehand, e.g. FFX bosses if you have some charged overdrives or Trails bosses if you walk in with some S-Crafts, etc., but there the bosses can eat that damage again in a long fight, so I suppose it'd apply to the durable ones too.
4) Re Elf on boss scaling, no need to rehash the argument again, but boss scaling via party HP in Suikoden is a compelling argument
for it if you're in favor
. Pretty much just a philosophical difference there: is a boss who requires 40 PCs to take down (Raid boss Onyxia, say) just by definition the biggest badass, even if it goes down in two rounds of offense? Well.. maybe. Totally an interp that says this boss is an awesome, and an interp that is more skeptical, and both are fine. (Not to mention issues like Fire Emblem games, where you might technically have 12 PCs on the field, but the nature of FE combat makes it more like 12 separate 1v1s...)
I will say as a side note that to the extent that a bunch of the conversation above is about in-game effectiveness... Safer Sephiroth with double HP but facing 6 FF7 PCs would be considerably weaker, and Lucia with half HP but facing 3 PCs would be considerably more dangerous. Which is exactly why when Lucia fights you without your full party, the game designers made her a wimp.