"Isn't it cute?"
Is this another way of saying " かわいいですね" ? Which is more commonly used? Also, which phrase is more rhetorical and which one is more interrogative?
かわいいですね。Is simply a statement. Adding a question mark to the end makes it a statement that requests confirmation. 'It's cute, huh' or 'It's cute, isn't it'.
かわいくないですか? used colloquially could mean, 'Isn't it cute?' rhetorically. However, it could also be interrogative, depending on the intonation and context.
'I'm not really fond of the new members of the group. Why not, are they not cute?'