Menu - how many options

It’s definitely not too many choices. It’s on the very limited side. What are the exact dishes you have in mind? Be very specific on your reply cards because someone may have allergy or aversion to a topping or a side and go with a different choice if they have specific information to work with instead of guessing based on “chicken “, “beef”, “vegan” and not having any idea because those cover such a wide variety.

If you’re serving buffet style, they don’t need the knowledge beforehand. But you do need to find out if anyone has dietary restrictions or allergies.

I disagree with PP that this isn't enough options, I think it's definitely plenty. You're talking two entrees, two cold sides, FOUR hot sides, two dessert options, and a late night snack. More than enough, verging on too many for the hot sides. I'd stick with two hot sides if it was me (and I am for my wedding, lol)

Yeah huge appetizer spread of charcuterie boards, grape leaves, dips and dipper things, maybe some savory phyllo thing like spanakopita or boreka or a GF savory biscuit

For the dinner proper:

Cold sides am thinking this raw marinated carrot salad (morkovcha) and something like a fall kale salad (it's in October) or a kale-based tabbouli. Potentially a lentil salad if no beans as a dinner side

Proteins: saffron-braised chicken with apricots, tempeh/mushroom stew with lager sauce (honoring both sides of families)

Sides: idk, maybe a rice pilaf, harissa sweet potato (or something less spicy, IDK. this is not "hot" but I'm considering if people will like- aka boring members of families (friends and some family totally into this). Another option is this za'atar sweet potato bake), bean dish (unsure yet- ones I'm known for is this Balkan paprika baked beans thing, or white or favas in a lemon dill sauce. Or a lentil thing), and a green thing? A side note is that it has to be something made in advance and reheats well. The pilaf will be baked day of so not the usual issue with rice not reheating well.

Um, not sure about a reply card? IDK is that for formal invites or something. We aren't doing formal invitations just a website thing where they click yes or no basically and let us know any dietary issues (but pretty much we know all our guests' stuff already). This is a buffet they can choose whatever they want

Invites and some sort of reply system (including cards for anyone who is not tech savvy) are a must regardless of formal or casual. You need to know how many are attending so that they fit at your venue, you can afford to properly host them and you do not run out of food/beverages.

Our venue accommodates hundreds of people just inside (and there are acres outside we get too) so that's np about capacity (we are inviting ~125 expecting 100,)

Of course we will know who we are expecting or not, we talk to all these people in person (will also have this e-vite thing but anyways)

I don't think running out of food/bev will be a problem. I've never had that issue in scores of events of this size I've done and I always end up cooking for a larger crowd than the min by 10-20%, usually that's right on the amount needed.