I find it very natural to love or at least have very warm feelings for my sub/slave, as I really would have difficulties having any "fun" with a person, whom I don't care for.

It can of course result in some of the more unpleasant "vanilla" phenomena, divorce etc.

I'd never had any problems punishing my sub/slave if she haven't done her duties. Because ven though you love and care for a person you don't have to be soft.