Aside from risking death to go to her balcony and drinking poison to be with her in death, what else does Romeo do to be with Juliet?

He marries her, for one. When Romeo spoke with Juliet, he in her garden and she on her balcony, she told him that if he wanted to marry her, she would send someone to him the next morning to get the details of the arrangement. He goes right away to Friar Lawrence to explain that he wants to be married to Juliet, and the friar marries the pair later that afternoon.

After their secret wedding, Tybalt challenges Romeo to fight him, but Romeo refuses now that he is related to Tybalt by marriage. He repeatedly tells Tybalt that he loves him, even though Tybalt cannot possibly understand the reason why.  Mercutio interprets this as a "dishonorable, vile submission" (III.1.74). Romeo didn't care about appearing dishonorable to his friends, however, because he was trying to honor his wife.

After Romeo and Juliet spend their wedding night together, Romeo is willing to be found there the next day by her family rather than leave her. He says, "Let me be ta'en; let me be put to death. / I am content, so thou wilt have it so" (III.5.17-18). He is willing to be killed by Juliet's family rather than to do something she doesn't want him to do: leave her.