First BBQ Party - Need advice on the menu & making as much in advance as possible

So we just got this wonderful big mountain home for family gatherings etc three weeks before Thanksgiving. Basically 10 houseguests over the holidays and long weekends it would seem, constantly. :) I do most of the planning/shopping/cooking. I don't mind it but need to find ways to make this all day entertaining a bit easier. Which brings me to Memorial Day.

I BBQ pretty well. I'm not a pit-master, but whatever I put on will come out edible if not pretty decent. I've grilled many things (but for me and my husband only - never a group). So I have some questions this being my first larger BBQ (12-15 people so far). Facts are I want to keep it a little southern themed (I'm doing a terrible job) and there are no dietary restrictions.

1) How do you time the cooking of burgers and sausages? Do you grill to order or in batches? Good idea to hand it off to a guest who BBQ's as well?
2) I am guessing keep it pretty simple with the burgers? We have a good butcher so I'd like to keep the focus on the meat. Like a 7/2/2 seasoning & toppings and a good grilled bun?
3) For condiments I'm thinking thin sliced raw red onion, homemade pickled red onion, homemade sweet pickles, iceberg shreds, sliced tomato, yellow mustard, ketchup, creole mayo (a cool recipe I found using...), homemade whole grain mustard,
4) For max 15 people, I'm thinking the following menu (please PLEASE add/subtract/debate - this is my first time).

FINGER FOOD/SNACKS:
- Homemade Guacamole, Store-Bought Deli Salsa, Tortilla Chips
- Caprese Salad Two Bite Skewers w/ a good Bottled Balsamic Reduction Drizzle
- Sweet & Salty Pecan Mix (Homemade)
- 3-4 Cheese Board with water crackers and grapes/honey/figs

MAIN:
- Topping's bar (veg/condiments)
----> Homemade Mustard & Creole Mayo (made ahead)
- Simple Burger w/ 7/2/2 seasoning on Grilled Kaiser Rolls
- Beef Hotdog
- Bratwust

SIDES & SALADS:
- Arugula, Watermelon, Mint and Feta Salad with Citrus Vinaigrette
- Ding's Cole Slaw (which is from Hillstone restaurant and fantastic)
- Louisiana Style Potato Salad
- Homemade Bread & Butter Gherkins and Sweet Peppers
- Jalapeno Corn Bread

DRINKS:
- It's Asheville, so a bunch of local beers in a big ice bucket - say 36? They won't go to waste. :)
- 4 Bottles of white and 4 of red
- Some type of sparkling sangria perhaps? We keep a decent bar if anyone wants something harder.

DESSERT:
- Alton Brown's Blueberry Buckle (warmed) with vanilla ice cream
- Magnum Ice Cream "Pops" (from the freezer aisle but oh so good) LOL

It's just me doing most of this and I think I can do most of this before hand. Lots of prepping then assembling day of is what I see here. Any help would be most appreciated and I'm open to criticism so please be honest.