What do you think about a person who strips naked in the middle of a busy area and pees in public? Should they be allowed to do whatever they want if they're not in someone else's private property?
I don't really support the idea of widespread private property outdoors in the trespassing sense. I find it to be a value that the offshoots of Europe (e.g. Canada, U.S., Australia, New Zealand, etc.) value more than the Europeans themselves. They are more likely to just freely roam around.
http://en.wikipedia.org/wiki/Freedom_to_roamThe nudity part doesn't even register with me as being worthy of discussion. But even if they were having a heroin-fueled orgy on the sidewalk, I would just walk around them and that would be that. I grew up around sex, sex toys, drugs, etc. and don't feel psychologically damaged or anything due to having that exposure. The urine you speak of would be concerning. Perhaps a decentralized urine-related ordinance in which people get allowances of x amount of emergency peeing outdoors in y amount of time? And/or perhaps allow unlimited public peeing provided that pee-collection devices are used. But private businesses could set their own rules concerning that.
Even if it didn't affect others I'd still think it's wrong, but to call it interfering with people's lives is quite simply ad hominem and red herring at the same time.
Stomping out imagined bad behavior before it even exists is interfering with people's lives. If someone's imagination goes wild, that's their own personal issue and they shouldn't drag others into it (and people they don't even know at that). Pattern recognition can be a helpful tool to make sense of the world, but when it's used for making laws, that's called discrimination.
THE UK CHANCELLOR OF THE EXCHEQUER the second most powerful man in the UK his opinions on new laws