I will advice you to get your I-485 first ,. it doesn’t take long .. also I think once you are married and you put in your application. you are no more F1 .. Also , make sure you update your international office and ask them questions

Both of us conditions are looking same. I just took one more class that was 3 months, after application. Everybody recommended to continue the school to me.

it won't affect your ability to obtain the green card if you fall out of status...you will be still be legal as you are in the adjustment of status category. However, if your i-485 is denied, you must leave the US pretty immediately. Maintaining F1 status will enable you to stay for the duration of your visa, despite the i-485 being denied.