Performing Salaah in jamaat with a na-mahram man

Q: I wanted to know a couple of things concerning the validation of prayer. If a man and a woman are in a haraam relationship (adultery), can he lead her in prayer alone? If a women is at a female friends house can she pray with her friends husband and son? If a women comes into the mosque and there are no other females and only one male there already praying should she follow behind him in prayer?

Conditional talaaq

Q: My question is my husband gave me a first talaq in 2005. We lived in ... for 8 years after that. He asked me to go back to Pakistan to live with my parents after a conflict. He gave me a second talaq via a text message while he was in ... and I was in .... At the same time he sent me an email with a 'conditional talaq notice' stating that he is giving me 2 talaqs on the condition if I come back to ... from ... and they will become valid and that first talaq of 2005, three talaaqs will happen and I will become na mahram for him. I stayed back in ...,then he sent me an email before 90 days, which was the iddat period for the second talaq he gave me earlier via text message, stating that he wants to make rajoo' with me and wants to take me back in his nikaah. After that the 2 conditional talaaqs are still there. My husband is still in ... and I am in ... Is that conditional talaq going to effect my present nikaah in any way like making it makrooh or do I need to do any thing about it so that it does not effect our nikaah?