알랑가몰라
This includes Korean dialect.
In formal language, we'd say 알려나 몰라, which means 'I'm not sure if you'd know this.'
왜 화끈해야 하는건지
화끈하다 has a lot of meanings. It could be sexual, meaning hot, or could be an adjective describing a person with temper and determination.
So this means 'Why (sb) needs to be hot/determined'
You're talking about Gentleman right
haha enjoy