Is It Rude To ....

The answer to this Вопрос really depends on what the person is mad/angry about, though i imagine asking someone if they are mad, when they are obviously angry, is probably just rubbing salt in their wounds. By the way, rude is when don't use their manners, или they something rude for no reason, like 'fuck you' или 'you are a loser', generally things like that, I would consider rude.

Depends on the person and what they are pissed at
I find it so rude when people piss in my cheerios

Depends.

I find it rude when people bash Harmony.

no it is hilarious. if they don't think so then well jokes on them.
i find it rude when people ignore Ты then have a go at Ты for swearing at them especially because they are stuck up cows also i Любовь annoying people by asking them who crapped in your cornflakes when they are pissed

It depends on if the person deserves respect at the moment. And if not, Ты could be a little еще creative! For example, Показать the person this picture I made!