Can someone help confirm this for me?

I think we can all agree, that when the subject consists of 2 or more persons that are referred to with the 3rd person pronouns, the subject is equivalent to the pronoun "sie (pl)" in German.

> 
> Alex und Hanna (sie) sind beste Freunde.
> 
> 
> Maria und ihre Kinder (sie) leben in Deutschland.
> 
> 
> Deine/eure Familie und ihre Familie (sie) sind miteinander verbunden.
> 
> 
> 

Now here's where it gets tricky for me. In grammar websites people have said again and again, that the rule is as follows: When there's a 1st person pronoun, the subject would be equivalent to "wir" in German, whether a 2nd or a 3rd person pronoun follows after it.

> 
> Du und ich (wir) sind verheiratet.
> 
> 
> Seine Kinder und ich (wir) sind beste Freunde.
> 
> 
> 

All this time I used the "sind" (pl) verb conjugation, because I thought with "und" it's always "sie(pl)" and not "wir". I am however pretty sure that the circumstances do not matter, because "wir" and "sie(pl)" are conjugated the same way (sein->sind) (haben->haben), so no confusion there. My question is, is it right then, that in a case like this you truly conjugate it according to the pronoun "wir"?

And then comes the tricky part, part 2.
When the subject consists of 2 or more persons that are not in 1st person, they would be conjugated according to the pronoun "ihr".

> 
> Du und er (ihr) habt euch erst gestern getroffen!
> 
> 
> Ihr und eure Freunde (ihr) seid zu meiner Party eingeladen.
> 
> 
> 

That is also what is stated in grammar websites. However someone has told me yesterday, that with "Sie" (even though "Sie" is here 2nd person) it would be conjugated like "Sie" would. (This made sense to me too, because I found no examples with "Sie" regarding this case in grammar websites.)

> 
> Haben Sie und Ihre Familie (Sie) heute gefrühstückt?
> 
> 
> 

Can somebody tell me if these informations are right?
In conclusion, are these statements correct?

> 
> 1. 3rd and 3rd person : sie
> 2. 1st and 2nd/3rd person : wir
> 3. 2nd and 3rd person : ihr
> 4. Except for Sie, (Sie+3rd person) : Sie
> 5. Are the example sentences also correct?
> 6. Are there any mistakes I stated that I should watch out for?
> 
> 
> 

Many Thanks!