Threatening to poison one's co-wife

Q: I married a Muslim man as a second wife. When his first wife was informed, she threatened to poison me, my (our) husband, the children and herself. I am new to Islam and my husband is teaching me about the religion. I have no idea what to do as my husband now fears for the lives of his children as well as our lives. Can she force him with these threats to divorce me? Please tell me what to do! 

Using interest to offset bank charges and disposing of interest money

Q: I have both a current account as well as a savings account at the same bank. On both the accounts, the bank levies bank charges, but the savings account is interest-bearing.

In this situation, can the interest received on the savings account be used to pay the charges levied on both accounts by the bank?

If not, then to whom should the interest be given? Can it be given to non-Muslims and even to street beggars or beggars knocking on doors every week?

Leaving Muzdalifah before wuqoof

Q: A friend and his family were not able to stay in muzdalifah on Youm-u-nahar in between fajar to tuloo', not even for 5 mins as they were forced to leave muzdalifah @12:30 (at night) as they were having toddlers and womenfolk with them, so they were not able to offer fajr namaz there in muzdalifah.

One mufti sb told that they should have left the women in mina and came back for wuqoof in muzdalifah, hence they have to offer damm. Another mufti sb told that there is no need for damm. Both are great Deobandi mufti's. What should they do?