Do we receive interests from conventional banks or dividends

Q: My question is that do we receive interests from conventional banks or is it dividend?  As far as i know, conventional banks use our money to invest and the profit received is shared among clients. Now, the money may have been invested in companies which we do not know if they are "halaal" or not.  But the question remains that is the money received is called dividend or interest?

Accepting funds or donations from Multinational Pharmaceutical Companies to run clinics in poor areas

Q: The Islamic Medical Association runs clinics in poor areas around Durban, where the Govt has no services for these people.  Funds are running out as more and more medicines are needed to help people.  So far no other money except those given as lillah by the muslim community has been used. Can a Muslim organization, in this case the Islamic Medical Association accept funds or donations from Multinational Pharmaceutical Companies to do its work in servicing the medical needs of the indigent population?  

Muslim Organization involved in Natural Disasters accepting funds from Haraam sources

Q: Can a Muslim Organization that is involved with disasters, eg., floods, fires, earthquakes, etc. use funds from haraam sources to do its work?  For instance, can they use funds donated to them from a Pop concert, or a financial institution dealing in interest related transactions like Investec?  What if the donations are not separated from the “halaal” moneys given to them by muslims and all donations are pooled together?  In most cases, the organization does not know where the funds are coming from.  The funds are deposited directly into their bank account, unless an organization like Investec tells them that funds are being transferred into their account.

Presents on Nicolas day

Q: I had today head ache what made me difficult to concentrate. I opened up the door to a sister who holds a present for my children. Because of my condition I did not realize what I did or was not able to correct situation. She is a Muslim sister and clearly said that this present is because of Nicolas. (In Germany we have Nicolas day in our schools. Children receive gifts from their teachers.) She is a neighbour and new interested in Islam and I work on her. I did not want to say it directly but later on explained that she should give such presents for the sake of Allah Ta´ala and earn thawab and send thawab to her dead father. But expressed my happiness about the present for my children because I know that she likes me and want to stay in contact with me. I told her that also there is no need for present if I read Yasin Shareef for her father and I cannot accept gifts. I am very sad that I did not react on the door before taking the gift. Please explain me if there was something wrong according deen. What would be wisdom? I know it is kufr to give gifts on a eid day of other religions but what is if accept them what I did but with the intention to bring to her attention.