I need to check many of these, especially balance questions, but for know i can answer:
QuoteAre the empty chests at the beginning of Treasure Isle hard-coded to be empty?Dunno but the point of those is that it has just been raided by another party (Champa pirates IIRC) so they're staying like that to respect the lore of the game.
QuoteValukarNever considered that he's limited by the specific summons the player has obtained. I don't think i'd change it but if i were to enable everything i'd definitively include Coatli as well, no reason to handpick some. Also it's very easy to play around Valukar's skill by summoning before he does.
QuoteDjinn StunI think it should be extremely limited cause it's actually frustrating to play against. Enemies messing with your gear shouldn't be the norm.
QuoteWould it be possible to add heal-over-time PsynergyIt's something i considered many times but always decided against. It's either irrelevant or favors turtle strategies too much
QuoteStun & SleepYeah they differ mainly by application and recovery chance, otherwise they're very similar. Your idea of Stun sounds like a powered up version of Delude though, so if i change it it's gonna be different from that.
QuoteTri-element classes seemed to make the run slightly easier compared to duo-element, characters were more durableTri element classes have the highest stat totals + the gap is often due to defensive stats so, perfectly normal.
QuoteI found some weird bug with item classes [...] Is it related to the change for the item classes where you need 3 element levels of the first 2 elements, then 3 of the 3rd, then 3 of the 4th?yes. I implemented it by creating new identical class lines with different requirements. I didn't consider it'd be possible to swap between different version of the same class step and now i'm wondering if it can be avoided somehow.