"Wanting somebody" means to me: "to want a certain someone around in my life". In younger days it had a sexual connotation, but as I've matured, I've learned a higher value.
"Somebody who would do anything to keep you" - scares me. It's obsessive and not realistic. I wouldn't trust a relationship with someone like that to be healthy...
I agree with moderation in everything. I also believe that a healthy relationship is one in which both parties enjoy the company of the other - enough that trust is built and growth is championed and supported. But nothing is taken for granted...
And there are others like me... never wanted to keep anyone. Not even wanting... But I do when I want to do it. Then like Kaiser Soze... gone, never to be seen again!
I like the first - "who wants you" - and have questions about the second - "would do anything to keep you!" To "would do anything to keep you" seems to denote an instability, a lack of bonding, a lack of togetherness, a lack of self-confidence, a lack of relationship. And, when should anyone be "kept?" A person is not property! Each of us has free agency - any time! I say - if he/she wants to go - then "go!" He/She isn't owned, captured, possessed, kept!
Yes, as to why I said, everything in moderation and there needs to be a balance.