Whoa, I think you got plenty of chili to go around! that's 320 cups of chili, I think you would be ok halfing that
Start off with a list of supplies, get all your non perishables early.
Create a list of guests.
Prepare for bad weather rain and wind, canopies, tie downs etc... unless you will be indoors, hopefully the weather will be perfect but I always say "prepare for the worst and hope for the best.
Make sure you have plenty of coolers and start making block ice way in advance... that is if you have a place to keep it, block ice will last 5 times longer than crushed. Separate alcoholic beverages from non alcoholic beverages, try to organize the coolers for example, Coors light on the left, Yuengling on the right.
Designated drivers... I know, I hate to be a "Debbie Downer" but this is a serious problem anymore!
Adequate seating and tables.
Cook your PP the day before and use a finishing sauce when reheating.
Double up on your pork, 16lbs is ok for a group of 30. 16 pounds with a yield of 50% gives you 8 pounds and at a quarter pound per person that's 32 servings (I actually estimate 1/3rd pound per person).
Use small slider rolls for the PP to keep waste at a minimal.
If using solo cups, place a marker by the solo cups so folks can write their names on their cup
Memories - have some cameras or ask folks to bring theirs, if you have a cheapo digital camera or two, leave them out and put a sign out asking folks to snap off pics, or buy some disposables.
Music, create a playlist of music to compliment your brother, throw some music in that fits your guests as well.
Put the dog and cat away, not everyone loves animals.
Delegation... don't be afraid to delegate some tasks to others such as setup and decorations.
Do you want to be cooking when guests are about or do you want everything ready to go?
If you want everything setup so you can mingle, then look into getting chaffing dishes, these can be used for hot and for cold foods such as potato salads.
Make signs for everything, Trash, Recyclables, Beverages, descriptions of foods.
Also place tags by the foods with the ingredients for Gluten Free guests and folks that may be allergic.
Coffee, start a pot right away, many folks like coffee as their main beverage, also put out some hot water for tea.Don't forget sugar substitutes for our diabetic folks.
Keep extra toilet paper by the toilets and a plunger by each also.
Of course this list can go on forever but I said enuff already!
By doing all this prep work, you will have more free time to mingle, and wont be bogged down by the needy folks that need to ask where everything is constantly!
But most importantly enjoy yourself, have a good time, the more relaxed you are, the more comfortable your guests will be.