

You would probably be able to get away with the opaque water bottle as long as you aren’t trying to take it someplace where those water bottles are forbidden. For instance, a sporting or concert venue might only allow you to bring such a bottle in if it is demonstrably empty, since that is such an obvious way to bring in a beverage that the venue would prefer to sell to you at 3-5x the normal price. And again, if you’re obviously intoxicated or otherwise causing problems police might take a closer look anyways.
Apart from the public drinking being a possible issue with what you describe about the public space parties, many jurisdictions have noise ordinances that would prohibit the loud music after a certain hour, often 10 PM. Usually only specially designated areas, like outdoor concert venues, would be allowed to make a lot of noise later than that. But again, for that to be enforced you’d have to be making a nuisance of yourself enough that someone would call the police. That’s the case with a lot of the laws: you have to be so egregious with it that you attract police attention or aggravate someone enough that they call the police.
And some attitudes are changing. A few years ago my state passed a law allowing local jurisdictions to designate a “social district” where public drinking is permitted. This is usually in a downtown area where there might be multiple restaurants/bars/music venues and maybe stores that are open at times that cater to when people are drinking. The areas are clearly marked with signs and if you pass them the alcohol becomes illegal, and I think the alcohol needs to have been purchased inside the social district; you can’t just show up with your own (cheaper) alcohol from home.
Where consider that down in parts of Florida where college students used to go party a lot for times like Spring Break, there used to be a lot of public drinking but the mass crowds of intoxicated young people, often vomiting and urinating all over in public, became obnoxious enough that local residents stopped caring about the tourism revenue and passed laws to crack down on this behavior.