Yes, the office at Islamabad is very slow. There is nothing that you can do to speed them up. Your only other alternatives are to move to a different part of the world as workers and apply through the Visa Office that serves that country. However, CIC can still insist that the application be processed in your husbands country of citizenship instead. The other alternative is for you both to get to Canada some other way, such as him being a temporary worker or student, and then apply "inland".
No, the support letters do not have to prove income etc. they only have to show knowledge and support for your plans to return to Canada.
If a Guide states "original", it MUST be original. Some regions insist on this due to prevalent document fraud.