Q: distributor と wholesaler と importer はどう違いますか?
A: Distributor - usually someone who sends the products from the maker to the seller
Wholesaler - someone who sells the products in large quantities
Importer - someone who brings the product into a new country from the country of origin
Q: if we were able to raise the distributor fee, would that work for you? と if we were to raise the distributor fee, would that work for you? はどう違いますか?
A: The first sentence might raise the question of your ability to raise the fee. The second one is more about the possibility of raising ....


Q: what does 'distributor' mean in this context?
A: A distributor is someone who ships and delivers a company's products. So in this context, it means warehouses where they keep the products and "distribute" them to their clients' addresses.
Q: We have contacted to the distributor of the manufactory. We will talk on this item with them directly, thanks you and we will get back to you if it is necessary. この表現は自然ですか?
A: We have contacted the distributor of the manufactory and will talk about this with them directly. Thank you and we will get back to you if necessary.
Q: ​​If you would be interested in becoming our distributor, please refer to the attached catalog and let me know which items you have interest.
We will provide the quote for you ASAP.
We look forward to hearing from you soon. この表現は自然ですか?
A: "...which items you have interest in." OR "...which items you are interested in." works too.

^Just some grammar changes.