Is the House of Representatives Too Small?

Facts

1. Research shows that as districts get bigger in population, constituents are less likely to report that they had contact with their member of Congress, less likely to think their member would be helpful, and less likely to favorably evaluate their member of Congress.
2. Our House has less members than both the British House of Commons and the Germans Bundestag, and Germany has 80 million people and Britain has 60 million people. 
3. Only about 20% of people support increasing the size of the House, whereas 60% are in favor of keeping it the same and 20% favor decreasing the size.
4. When asked whether they would support increasing the House to improve representation of minorities and women, support goes up to 48%.
5. Most support for a larger  House comes from Democrats, women, and African Americans.

Questions

1. How do Representatives go about trying to keep in touch with all the people (nearly 640,000 citizens each) that they represent?
2. In what ways would having smaller districts and more Representatives benefit the people?
3. Could a larger House slow down progress?
4. What is the argument for not wanting a larger House? Is one reason the possible tax increase that would result from this change?
5. Do minorities feel as if they are represented in our current House?

Personally, I do not think all of our diverse population is fairly represented in government. In larger districts, the minorities do not have a representative to reflect their needs, which tend to be overlooked in our current House. I think we should increase the size of the House to better include all people, but not so drastically that our taxes totally shoot up. 150-200 additional members of House would do our country well due to the ever-growing population that deserves to be fairly represented in government.