Is it permissible or forbidden to deal with the Arab Islamic Bank in the West Bank, deposit money in it, and work with the Murabaha system, especially for someone afflicted with obsessive doubts?

It is not correct to rule that dealing with Islamic banks or conducting Murabahah sales through them is absolutely forbidden, because some of them adhere to Sharia guidelines and have a Sharia supervisory board. A Muslim should seek out the bank that is most committed to Sharia guidelines when dealing with it, and ensure that these guidelines are present in the transaction they desire.