Yazık oldu

It's risky. It can sound like you're saying their life was a waste. Stick to 'Başınız sağ olsun' for condolences.

'Yazık' is a general exclamation (Pity!). 'Yazık oldu' is a complete sentence (It became a pity/It was a shame).

It is neutral. You can use it with your boss, your friends, or a stranger on the street.

Yes! That means 'It will be a shame' (referring to the future).

You say 'Paraya yazık oldu'.

Yes, it's a strong expression of anger/shame. Don't use it unless you are very angry at someone's behavior.

Absolutely. It's very common for minor daily mishaps.

Technically 'Yazıklar oldu' exists, but it's very dramatic and rarely used in modern speech.

There isn't a direct opposite, but 'İyi oldu' (It was good/It served them right) is used if you are happy about a result.

Only if you have a close relationship with the person. Otherwise, use more formal language like 'Üzüntü duyduk'.

Yes, it is a universal expression across all dialects of Turkish.

The 'tsk' sound is a non-verbal way to express 'no' or 'regret' in many Mediterranean cultures, including Turkey.