I've talked to Pyro directly about these, but might as well have my thoughts on here for posterity.
1. Should Adamantine equipment (Katz Corner shop) stuff be allowed? This requires getting ~5000 Katz souls over the course of the game and unlocking chests with them.
Getting enough Katz souls to get Adamantine is super-trivial, I can't see any reason to disallow this. It's not that different from allowing top-tier equips in other games that like... cost 25% more gold resources than the previous tier, in a game where you are swimming in money.
2. To what extent should equipment enhancement be allowed?
[My initial thought was that this would be limited to a certain number of items per PC... 2 Adamantine, 5 Gold, 12 Mythril, 16 Topaz, 25 Quartz, 30 Feldspar, 14 Silver, 37 Amphibole, 40 Flourite/Amber/Bronze/Calcite]
This sounds fine to me. If anything, you've erred on the low-end of potential endgame enhancements. Most players probably won't play around with enhancement options until lategame, so they'll have plenty of resources to devote to their higher-end equips.
3. With regards to equipment enhancement, most gear has a 'secondary skill' that unlocks when you enhance it, with the exact # enhancements randomized. Which equipment secondary skills should be allowed, since the better gear generally requires higher Enhancement levels, but it's random what # it unlocks at.
[ Initial thought was to allow secondary skills for equipment for stuff other than Gold/Adamantine]
I'm pretty ambivalent here. Allowing them for easily-maxed equipment sounds fine, but I'd drop them, personally, just to make the math easier.
4. Should other things in the DL be considered to have a changeable "Soul" level? If a PC uses a Soul Break it normally drops their souls by one level and increases the target's by one. Vice versa for inflicting status/stun. Should we assume enemies have 3 starting souls and can get moved around by the actions of the Berseria PCs, or just lock them to 3 souls always?
I'd allow them Souls that act like in-game. Functionally all this does is make the ToB Cast's status rates more closely resemble actual in-game status rates, so go for it. (However if this makes the math more difficult, it's fine to just set it at the neutral 3, too.)
5. How should Stun be handled? It normally takes 1000 stun 'damage' to stun, and the formula is (relatively) known, along with averagish enemy Focus. Should we maintain the 1000 Stun threshold, and does that make the cast too good if they can all hit it in one turn? Should Stun's damage doubling be factored into a damage average?
Stun works on literally every enemy in the game, even when other statuses can be immuned, so I'd say it's almost akin to how we tend to view the "stagger" state, linking combo strings together for other Tales games. Include it as a universal thing all the characters can do, and definitely include the damage doubling in the average where appropriate. Other games with characters that have an explicit "Stun Immunity" wouldn't count as nullfying ToB Stun to me, since the status works in a fundamentally different way and bypasses normal status immunity.
6. Starting BG. The resource to use Mystic Artes (BG) is restored when staying at an inn. Should this mean it it starts full in the DL? Or should it be half-full or even start at 0? This matters because Mystic Arte damage is so huge that starting with BG will inevitably mean the cast is defined by unleashing a murderous (probably Stun-boosted) Mystic Arte.
Mystic Artes are a big part of ToB's system, and even if you don't run to an inn all the time, it's relatively easy to increase BG over the course of a dungeon in normal fights. So... much like every other Limit Break-type system, I'd go with setting BG as 50% max. I know this means that none of the cast ever sees a Mystic Arte Lv2, but it guarantees they can all use a Lv1. The sheer disproportionate strength of MAs means that most of the cast STILL ends up being "huge frontloaded damage monsters", but not to such a ridiculous degree that allowing full BG does. (And it also means that they might be able to status-stall/drainheal-stall their way to a second Lv1 MA in some fights.)
7. Arte * Levels. The best titles (Combo Artist) boost artes based on their * level, or number of uses. I was thinking 2.5 Stars for everything would be fair (since you'll have some that are above this, and some below, and if you even out your arte usage without much favoritism you probably end up around here). I wasn't sure how to approach this and it matters to a certain extent, but 2-2.5 stars feels right.
Pretty sure this interp was my personal suggestion, so obvs I agree with it~
8. Enemy difficulty affects enemy stats slightly. I think "Moderate" is the right difficulty to take (3rd choice out of 6, since it goes Easy-Normal-Moderate-Hard-***-Chaos). This shouldn't matter too much.
Sure, Moderate sounds good, doesn't really affect much, so might as well.
9. On a related comment, should bosses be considered for the enemy Focus average? (which affects status/stun infliction). Normally bosses aren't included in determining status accuracy in other games, and I'm not sure if it's a penalty to the cast to do so (and then also allow them to be immuned).
I wouldn't include Bosses, but based on the preliminary numbers I saw, the ToB cast already has pretty decent status rates, so it's not a huge deal either way.
10. Is there any objection to just assuming all the equipment Master Skills are known? It might be difficult but your PCs will know a mix of them and it shouldn't matter too much.
Most of these don't effect much, and most of them are 100% unique to specific characters, so normal DL uniqueness rules would allow them, even if they don't matter much.