It can be used to show an Intimacy. The actual meaning is fool, but it can imply cute.

I love that word. it is sweet as well we usually use that word to people whom we like. I use that word to my sister, my brother and my boyfriend lol

Of course you can, my friends call me that at times!

바보(a fool) sounds standard, vintage, childish, literature, naive, etc. It is not that much offensive. An offensive word would be 병신(a lame).