กล้วยๆ

No, it's too informal. Use 'สะดวก' (sà-dùak) or 'ไม่ยาก' (mâi yâak) instead.

Mostly, but it can also apply to games, exams, or even opponents in sports.

They are equal! You can use whichever you prefer. 'Kluay-kluay' is perhaps slightly more common in Bangkok.

Reduplication in Thai often turns a noun into an adjective or adds emphasis. Here, it creates the idiom.

Be careful. It can mean they are 'easy' in a negative, pushover sense. It's better to use it for tasks.

Not exactly, but 'Durian' is often used to describe something prickly or difficult to handle, though not as a direct idiom for 'hard.'

It looks like this: ๆ. It's called 'Mai Yamok.'

Yes, it's very common and polite enough for children to use with friends and family.

No. In Thai, 'bananas' only means 'easy.' To say 'crazy,' you would say 'Bâa' (บ้า).

Yes! If something is incredibly hard, you can roll your eyes and say 'กล้วยๆ...' to show it's actually a nightmare.