I am currently on H1B visa. I am going back home to stamp my visa on my passport soon.
I am getting married this year to a green card holder. Is everything okay with that? What if I marry him before I stamp my visa? (my status has already been changed to H1)

Maintain your H1-B until you get your green card.

Yes, the H-1B has statutory dual intent. For clarification, consult with an immigration attorney. Congratulations.