ร้อนมาก

Only in the compound 'Jai Rorn' (impatient). Calling someone 'rorn' directly doesn't mean 'sexy' like in English; it just sounds confusing.

'Maak' is more objective and standard. 'Jang' is more emotive, slightly more feminine/cute, and used for personal feelings.

Say 'Mai rorn' (ไม่ร้อน). If you want to say 'Not very hot,' say 'Mai rorn maak' (ไม่ร้อนมาก).

In Thai, adjectives like 'rorn' function as stative verbs. You don't need the word 'is' (pen/kue) before them.

They are referring to the physical temperature of the food, warning you not to burn your tongue.

The opposite is 'nao' (หนาว) for weather/feeling cold, or 'yen' (เย็น) for things that are cool/refreshing.

Yes, as small talk before the interview starts, but add 'kráp' or 'kâ' to be polite: 'วันนี้อากาศร้อนมากนะครับ'.

Yes, 'rorn ngern' (hot money) means you are in desperate need of money quickly.

Technically yes, but in Bangkok and casual speech, it's often softened to an 'l' sound or a very light tap.

Use 'rorn sud-sud' (hot to the max) or 'rorn chip-haai' (extremely hot - but be careful, this is vulgar).

Yes, 'seeโทนร้อน' (hot tone colors) refers to reds, oranges, and yellows.

Sometimes, like 'hot issue' (pประเด็นร้อน), but 'dang' (famous) is more common for people.