Alright, so first of all, to answer your first question, I think it would be best to tell an admin if someone is swearing through teamchat, and not tell him to quiet down yourself. if it's in all chat, it goes without saying that you should let the admin handle it.
Typically, if someone tells me someone is swearing through teamchat, and I'm the only admin in the server, I tend to switch teams and just watch. This tends to calm people down, to know that an admin is watching them. This is also typically more effective than if an e yells at them.
As for reasonable time... It's a tough one. I will typically address problems as quickly as I can, but realize we can only type at a limited speed, and certain messages are long. for simple swearing, I know it's tough to do, but if an admin hasn't answered it in a minute or so, it's probably best to let it slide. The admin might have chosen to let it go (because everyone makes mistakes every once and a while) or the admin may not have seen it. If it only happens once, then it's probably not a problem.
However, if you see an admin ignoring someone blatantly swearing more than once, you need to ask them. Tell them in admin chat. If they don't respond to you, you should phone up another admin or even an advisor on steam (which all e's should have in their friends list).
Now, that said, don't accuse the in-game admin of negligence. Yes, they should have done something, but perhaps they were getting a status/ recording of that guy, or maybe... anything. Typically, when we (admins) are in the console, we are more prone to missing chat messages, because we aren't really paying attention to that.
Don't worry about questions, by the way, because questions help to ensure you DON'T do something wrong in the future. It's a good thing you asked them, frankly, because I've found in my teaching experience that if one person has a question, there are at least 5 others wanting to know the same thing.