Yes, it's slightly more colloquial, can be a bit older, and can also mean boyfriend.
When you say "pojke" you talk about a child but if you say "kille" you talk about a male. I hope you understood
Just to be clear, though: a pojke is a male child, not a child regardless of gender.
No, there's no age difference between the words. The only difference is that pojke is an older word while kille was added to the language in the 60s.
There definitely is a difference in age. I use kille all the time for adults up to the lower middle-aged range. I would never use pojke like that.
When playing football in "korpen" we kept using the word "pojkar" even when the players were 83 year old... And I could certainly use "kille" regardless of if I was talking about an infant boy, a teenager, an adult or a senior citizen - but never when writing about a boy/man in a formal text. (native)
Yeah, formal text is something else.
I won't question your own native language, but I still think kille is a lot more versatile. You might say jag känner en kille som ... in your 50s, for instance, but I doubt anyone would say pojke där. You could talk about killarna på kontoret, but pojkarna makes it sound a bit like a pilsnerfilm, and so on.
What type of accent/tone does 'pojke' has? Is it like 'en man' or like 'kvinna' ? It's hard for me to make it out.
It is hard trying to figure out the pronunciation of this. Is it like "Poyike" or "Poyke"
When referring to an animal, like en hund, is it proper to call it en pojke or en flicka? Or do these names describe only people?