He's an elevator operator: his days consist literally of nothing but going up and down—rising and falling. They are therefore "days of rise and fall". That's very boring, so he needs something to "fill" his days and keep them from being wholly monotonous; so he writes in his notebook everything that is not just rise and fall, rise and fall.
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
As a British English speaker, I find "What was that all about?" perfectly normal, after something said or done that I find inexplicable, either as a direct question to the sayer or doer, or, very often, as a rhetorical question to another bystander. In the latter case a possible response might be a shrug, or rolled eyes, or both.