There are many dialects in English. In some dialects, "you was..." is used.
Here is an example, the song "You was right, baby." (YouTube)
Lyrics:
you said someday you’d turn the tide,
and i’d be laughin’ on the other side,
and you was right, baby,
baby, you was so right!
you said someday the worm would turn,
i had some lessons that i had to learn,
and you was right, baby,
baby, you was so right!
(Metro Lyrics)
Your school teachers were probably teaching you the dialect called standard English, according to which you was... is not considered correct.
The question seems to focus more on religion than on sports or hair style.
A religion is a practice not a belief. You might not believe religions exist until you see people go to a place of worship. So religions are a fact, not a belief. They do exist.
However, a religion's followers share their beliefs in theological matters.
So if you see someone reading a holy book, pertinent questions might be
Do you follow a religion?
Do you practice a religion?
Which religion do you follow?
But if a conversation has given you a hint that it may be so, you can ask
Are you religious?
I would not use that as an opening line for a conversation, it needs to be led towards by "small talk" to get a conversation going, unless you have an encounter with someone reading a holy book.
I realise I have side-stepped the question about "a" or "any", because I would not say it like that at all, and I hope this answer helps.
Update:
In the second case, I think you can say "a team" or "any team".
The third case is harder.
Is there a girl with weird short pink hair at the party?
This implies you have seen or know the girl and want to know if she is at the party.
Is there any girl with weird short pink hair at the party?
This means you want to meet such a girl and ask if there is one like her at the party.
Best Answer
better for the both of us is a kind of set phrase, so this could be a witticism. You haven't provided much context, but I could easily imagine a "stand-up" comic saying it to the audience. It puts the audience in the position of the person to whom those words might be said in another context, and the conversations where that phrase is used normally have some uncomfortable element to them. It would be a kind of allusion to such an uncomfortable situation which casts the current conversation between speaker and audience in that light. I'm trying to be very general there, since the discomfort could be almost anything: