My wife and I play D&D together, and we're really excited about the BG3 release! We also both love classic Bioware style RPGs like Mass Effect. One thing I read, though, is that multiplayer dialogue can be a bit hit or miss, so I have a few questions.
1. I want my wife to enjoy dialogue since that's her favorite part of these kinds of games. She also wants to be a wizard. Can a wizard be the face? I feel like sorcerer would make more sense because of Cha.
Yes, there is nothing wrong with a Wizard with a few points in Charisma. I would warn you about using wizard spells like friends/charm person with anyone you want to have a long term relationship with as Charm will cause hostility. Also Intelligence does pop up sometimes in dialogue.
Having said that Barbarian with Intimidation is 100% better for the face. Barbarians get advantage a lot on intimidation checks.
Bards are the grand masters of party face - they get SO many different ways to handle situations it's crazy.
2. If my wife handles most dialogue, will I feel like I'm missing out on story or is it basically seamless? I'm happy to roleplay a stoic background character for the multiplayer run, but I'm a little concerned about missing cut scenes and being confused about what's happening.
You won't necessarily, however as long as your wife doesn't immediately skip ahead in the dialogue you won't miss anything and it will replay the part she is on from the point you jump in. You guys just have to exercise a little discipline and wait for the other person before moving forward in the convo.
3. Neither of us care about romancing NPCs, but we do care about side quests, origin questlines etc. and being part of a "team." Do you think this is achievable in multiplayer?
Very much so. To an insane degree. Or you can compete with each other. You guys really should take the EA for a spin, all the content is changing anyway so it really doesn't spoil anything.
4. Are side quests/rewards shared?
The XP is shared amongst the party regardless of distance. The items you guys have to decide who gets. Quest rewards are a choice amongst items or they are specific, or just XP.
5. I know dialogue just chooses the closest party member and/or whoever initiates dialogue, but are other players pulled in to observe automatically if we're within range? It'd be annoying to always miss the first ten seconds of something while I click into dialogue.
Sometimes you all get pulled in and it chooses the closest party member. if you are out of range then rules above apply, she just has to wait until you get close enough and you get pulled in or click on her and then you will see the start of the convo from the point she is at.
Additionally you can vote on dialogue choices, but only the face person can ultimately decide. I would work out a system with her in the case of a tie.