On the contrary, I settled down in front of TV mentally preparing for another dumb movie for kids, but found it much better than expected. Better, as in at least watchable. (It was my 9-year old that insisted to watch it).
To answer some of your worries, my son was not shocked and did not ask where do babies come from, since he has a pretty good idea about that.
Also, kids these days are not scared nudity and generally know it is 'censored' in many games and videos.
In fact, he rather liked the movie since it involved things like brotherly love and what being a family means, things he can relate to.
Frankly, I am surprised that someone as young as you, someone that grew up in the age of the Internet and smartphones, has this kind of issues.
I was raised christian wich ment my perants sensored most things from us. They would often watch movies before us to see if they were ok for us to wach (not animations of course) but my dad wasent very happy about this movie and stoped waching half way though. I never really got exposed to things onther kids my age did and a lot times they would know way more then i did. Take Harry Potter for example. I was never aloud to watch it untioll about number 5 or so was out and after years of begging. So things like this do catch me a little difrently then it would other people my age. I always say i was born in the wrong geniration coz im nothing like my 21 year old friends