Linking one's bank account with someone else's account

Q: Is it permissible for me to link my bank account with my father's bank account at the same bank which contains interest but I am not withdrawing any money neither am I depositing money from his account but just linking it? My account is interest free and the money in my account is not being shared with his money but the "link" is still there.  Is this permissible?

Three talaaqs

Q: I gave my wife 3 talaqs at once. On the Internet 75% of imams say marriage is over, while other imams say 3 talaaqs together count as 1. She told me Wallahi Internet is not accurate, & the imam said it counts as 1. I had intercourse with her because I believed she was truthful but I felt guilty. I have since given official shariah talaaq. Are we both sinful or does she carry the greater burden?