Being a witness to signing for a home loan bond

Q: I was traveling with a co-worker who stopped at the attorney offices and asked me to come inside with her. When I went inside I was asked to be a witness on signing for a home loan bond that was taken with the bank.

I am feeling very uneasy and I would like to find out if I have committed a sin by being a witness to the interest stipulated on the contract.

Can I somehow get my name removed from that contract as I myself try my utmost to not deal with interest bearing loans. 

Imaan is a precondition for Jannat

Q: If my non Muslim neighbour passed away and me as a Muslim assume that this person is going to jahannam forever and ever and ever. Then there is a hadith about a prostitute who gave a thirsty dog water to drink and she was granted entry into jannat. So is it right for me to think that the non Muslim neighbour is going to jahannam?

Getting married after khula

Q: I had khula in January 2021 due to circumstances and I have a baby as well. But I have strong feelings for my ex husband, even though I came to know he got married, but he did contact me and mentioned he missed me. After that he never mentioned it nor did we have any further conversations. I do feel I and him understand each other. Is it possible that by any type of prayer or dua I can get under nikaah with him again in any point of my life?