Huh, I don't know how the queen would be asked, it would probably have to be worded in a very fancy way. Here you're simply talking to multiple people, with whom you're not on a first-name basis.

Yes, it's formal, but no, it's not the best form for talking to the queen (you'd want to use singular, rather than plural, which is the form here). Hungarian differentiates singular and plural in both the formal and informal.

Simpler answer ... yes, this is the polite plural form.

"Maguk" is also polite plural form (but slightly less formal, also less commonly used).

I've heard it described that the "maga" article is formal, while the "ön" article is official. (So used, say, for government business etc.)

Shamarth, if it were people that you knew, but weren't on a first-name basis with, wouldn't you use "maga"?