Someone datamined the game a long time back (so this will have changed a bit with expansions and the content added to the base game), but what they found was that the most important stat for opening dialogue options was Perception, followed by Might and then Resolve. My experience of three play-throughs is that if you have 16 in those three (doesn’t matter how you get it - actual stats, items, buffs, food, etc.), you’ll have really good dialogue options, but that the Might ones were the least interesting (however there are a couple of places where 15-16 Might will help you in a non-dialogue situation). Most classes benefit from those three stats too - perhaps Priests the least because Might and Perception are less key to them.
The class/spec with the most specific options is Priest of Magran (slightly surprisingly - Priest of Eothas has less, despite the plot). All classes except Fighters have some. I had some really cute ones as Chanter (not many but they were cool and very bard-y), and Ciphers, being psychic, have some good ones too (but not the huge number they had in Pillars 1).
Diplomacy, Insight, Intimidate and Bluff are the main skills which unlock stuff - again it doesn’t matter how you get them up. If your party is nearby when you initiate dialogue (i.e. within about 20-30ft), you get the usual bonuses from them, which can be important (there are a handful of tests which don’t benefit from this, but they really are rare).
Race-wise, Island Aumaua (who are native to the Deadfire) get the most options, but again I think all get some. As Vailian human on my last run I certainly had a few.
Even things like backgrounds tend to give something. My Artist background came up a couple of times.
The most spectacular background one though is still in Pillar 1 where (spoilers) if you are a Nihilist Philosopher, when you find out the gods aren’t actually gods in the truest sense, you get to say “HAH! I KNEW IT!!!” in a very satisfying way.
So I think if you want absolute maximum options, get the stats I suggested (or close to them - you’ll soon find items that will raise them a little), make sure you have decent scores in the skills I mentioned (the social skills, naturally enough), and don’t pick Fighter as a class. You may also want to pick Island Aumaua, but I’d say race/class is more about making sure you have fun - most classes are pretty fun, so there’s that.
Also if you’re really min-maxing dialogue options (I know you aren’t, this is just to add it in there), women have verrrrrry slightly more dialogue options than men.
If you’re in it for the story and have limited time, I’d suggest Realtime and Normal (or Story) difficulty, rather than Turn-based. Turn-based is really awesome imo, but there is absolutely no denying it extends the actual time spent in combat by a lot over moderate pausing with Realtime on medium (or even slow) speeds. If you’ve got a bit more time than some, and you really like Turn-based games, then it’s worth it though.
Oh and if you have got any achievements from previously playing, and thus can turn on some of the bonuses - I’d say turning on +2 to all stats and double starting skills (in that order) are the best things you can have, for opening stuff up (and just generally making the game more fun near the start).
Anyway, hope it’s really fun. My last playthrough, with the beta Turn-based was pretty great, I have to admit - for me the Turn-based changed Deadfire from “great” to “Into my top 10” (which Pillars 1 never entered!).
Ahahahaha yes. The funny thing was, by the time Baldur’s Gate 2 came out, D&D 3rd Edition was well into production (hence it having a 2nd edition version of the 3rd edition Sorcerer class in it), and even before BG1, Wizards of the Coast had put out an article earlier in 1998 called “How you can played 3rd Edition right now!” or something like that, suggesting various rule-changes which would make 2E more like 3E - one of them, of course, was inverting THAC0 and AC and turning it into to-hit bonuses and increasing AC. It was noticeable that even with smart players who’d been playing D&D for 8-9 years, that actually did speed up play…