Would like to chime in on the Uncle thing:

I think something like this is more common in other countries, whereas it's seen as something 'Pedo-ish' here. Honestly, most words kids know from a different language usually refer to older strangers as 'Aunts' or 'Uncles'! I forgot specifically which language I'm talking about, though, so forgive me for the lack of evidence.

I do know, however, that as a child I'd always call anyone who knew my mom + was also Filipino 'Aunt/Uncle [Name]' (in our language, of course) as a form of respect, regardless of whether or not my mom knew them well or was friends with them.

It's kinda like a Mr. or Mrs./Ms. for kids, I'm guessing and their actual forms of Mr./Mrs/Ms. is more for formality? But, it also depends on where you're from. I'm just talking from experience from taking French and being Filipino, so I'm not actually sure if it's the case for any other country or language. ;o