Oy....so far I just read only the op and my head is spinning with trying to read the information/
What I have done and do now, and it is probably not approved in etiquette hell, is when I have something at my home, whether it be game night, or a holiday dinner, such as Easter dinner yesterday, if anyone asks to bring something, I might mention something to eat if they desire, but since usually everyone drinks a variety of drinks, I will tell them to bring what you like to drink. I simply cannot afford to buy everyone's drink preference and I do not want the leftovers. Usually, for instance my BIl and his girlfriend, always bring their own drink choice anyhoo. She drinks Mountain Dew, he used to, but now I notice he drinks a quart of some type of ice tea. We try and drink somewhat healthy in our home and don't carry those items usually. That does not mean, I will not go out and buy a variety of drinks at various times, it is just easier for most people to bring their favorite choice of beverage.
What you could do for future reference is have a certain number of drinks to offer and that is it. Say, water, ice tea and maybe a soda of your choice or a wine. For dessert have coffee and tea bags available. (I am a tea drinker, not coffee). But, I would not have too many choices as that can make it confusing.
Or you can put all choices on a buffet type bar setting and let people serve themselves.