:| I've never been to an 18th with security...I think that's kinda odd, tbh. I wouldn't have any. People are always gonna crash.
How would they know who's invited anyway? Don't tell me you're going to have actual invitations. Or will you have a list of people who are invited?
Also, it's in September, that's ages away! Half the people who've heard about it won't care or will have forgotten.
Honestly, I think you're being a bit over the top, it's not the end of the world. I wouldn't care...people have crashed all of my parties, all of them house parties. I'd care even less if it was at a hired-out place! I've crashed loads of 18ths and house parties, no one cares.