For anyone, guy or girl, tattoos are only attractive if they have some meaning behind them, the art is done well, and the piece is placed correctly. For a placement example: It would be a bad idea to get a memorial of a family member who passed away tattooed on your butt cheek. The examples you gave are pretty standard and boring, because so many people get those. But if the particular piece you choose actually means something to you for some reason, then go for it. Don't just get a tattoo for the sake of getting one, because it really doesn't make a person unique when they have something plain and common that millions of others have, and you'll regret it in most cases. That's just my opinion.
They can be, but it's all about placement for me. I'd rather them be small and in a spot like the foot, hip bone, lower back, etc. If there's a big tattoo on their arm (like Popeye), then that's not OK in my book!