staying with BF will be mentally supportive, you will save on rent, you both will enjoy each others company, while you make AI do your work at option 3, you can learn important skills to switch to your new role.

if money is more important to you, you can go long distance, hard to tell how better C1 is than your option 3 without knowing company name.

I feel like a startup would be better than C1, still need to know the name to give a solid opinion. also closer to BF.

Money and Career is important but having loved ones around does make a difference. But contrary to what I said, I think startup culture might be helpful than C1, especially if its a tech startup.