Romance novels always have a happy ending. Limit point of view to the heroine and hero. Our editors like the main story focus to be the relationship conflict. Sexual tension should not be confused with conflict, but both are vital. If there are no love scenes there should still be sexual tension.
Love scenes can be light to heavy sensual.
If there are love scenes, they should advance the story or characters and tastefully establish emotional intimacy rather than focus on the mechanics. Master the techniques and skills of good writing. Present a professional image. Self-edit to the best of your ability. Check spelling, grammar, punctuation, sentence structure and use proper manuscript format.