Levels of Affiliates, Membership and MarketPress

Dear Community,

Help needed as follows:

(1) Membership Plugin: Coupon Code & Invite Code:
Which file or where can I edit the words? Change the words "Coupon Code" and "Invite Code" to "Discount Code"?

(2) Subscription Types:
I have a three-level membership site. When a member registers for a FREE level through an affiliate link, will the same affiliate link go to Levels 1-3 automatically? Or does that member have to click the affiliate link again for each level?

(3) Affiliates & MarketPress:
One Store, Many Products:
I have a bookstore. An affiliate link is for the store only, eg. http://www.newbooks.com/?ref=aff007

3a. If a visit goes to http://www.newbooks.com/?ref=aff007, and click on a book, eg. http://www.books.com/book001 and purchase it. Will the affiliate link still work?

3b. An affiliate does not want to link to the whole store like http://www.newbooks.com/?ref=aff007. He wants to link to ONE book only, eg. book001. Can he have a referral link for that specific book? eg. http://www.books.com/book001/?ref=aff007

(4) Manual Payment Processors for Affiliates, Membership and MarketPress:
A manual payment gateway here , I mean there's just a simple page where the buyer fills in a few lines on how he will pay later. After that, the admin will confirm if the payment arrives. Then, the buyer can have access to the product or a membership area. Automatically, the commission is sent to the affiliate too.

Also, I am still waiting for the good news here: