Really sweet, but strong as well. Really unusual in English-speaking countries, but simple enough for people to pronounce easily.
Pronounced AY-uh-nuh, but without any pauses.
I think it's a lovely name. I live outside Ireland and it doesn't sound unmasculine to me, but each to their own.
If you live in the UK I'd recommend only using this spelling for the pronunciation LOO-ee. Any I've known in England have used that pronunciation, and used Lewis for LOO-is, so it'd avoid a lot of confusion.