Venus shows what a man is attracted to in a woman. Being with a woman who is strong in his Venus element, or who makes close sextiles to his Venus makes the relationship much easier, and increases sexual desire and compatibility. For a woman, her Venus is part of her feminine nature, so it is definitely best when her partner also relates well with this element. When people have positive Venus synastry, they naturally like and love each other. That, of course, is what makes positive Venus synastry so great.
Venus Inconjunct Sun
A Venus inconjunct Sun aspect indicates that your partner has very different ideas about how to create a romantic and domestic relationship. That's what intrigues you and attracts you to him/her. When the Venus person is inconjunct the Sun person, there's something about the way you look, the way you act, the way you love that they find very attractive because it is fresh and novel and so different from their ideas. You inspire each other but you will find yourselves having to adjust and adjust if you aren't going to let the little things drive you to frustration.