diy Food Help

My fiance and I both come from families and communities that cook a lot. There are a number of professional chefs on my side, even.
I have invite list with 400 names on it which os a ton.
But I don't want to have a catered feast of any sort. I came up with a pasta menu and broke down each constituent part into ingredients that would need to be bought. Rotini pasta, with a gluten free option, two sauces bought in bulk, pre-prepared meatballs or slow cooked chicken pieces, mushrooms or leeks and greens, and a few cheeses available. Plus fruit platters and garlic rolls on the side, ginger ale, root beer (fiance's fave), sparkling grape juice, or water to drink, and then sheet cake and chocolate punch for dessert. The way I wrote out the menu, it's on a spreadsheet with formulas that will allow me to know how much to buy of each thing depending on how many people can come. Still need to do formulas for how many crock pots and such would be needed. Has anyone done their own food like this? Our families love to cook and we'll have a good deal of kitchen space, and we're hosting at our church as an all-in-one venue. Where would I start testing the doability of this menu? How should I guage the willingness of a few cooking lovers to help with this? In both our families, and our church, family gatherings and fellowship gatherings always mean potluck. This isn't quite a potluck obviously, and we'll be paying for all the ingredients. But the church is equipped for this kind of thing, and around here we show our love and support with food. I tried to choose the easiest foods and methods to prepare. It'll still take a good chunk of time, but many hands make light work. Should I ask my aunt and great aunt about this menu? They're both professional cooks but also they're not my favorite people to talk to, they kind of intimidate me. Anyway... Thoughts? I'm really not prepared/wanting to cater at all. And this menu is way less labor intensive than hand smoking a hundred pork shoulders for pulled pork which is what my fiance originally suggested since his dad loves smoking pork. Pasta is typically seen as one of the easiest and cheapest wedding meals. Which it is, but I have years of experience elevating it to a lovely experience, so it wouldn't come across as tacky. I have many wonderings on this and not much time left. Less than 90 days... So yeah. Chip in with your two cents on how to make this work, please? Thanks in advance.