1.
Commission is a fee for services rendered based on a percentage of an amount received,collected or agreed to be paid (as distinguished from a salary); whereas discount is a reduction in the selling price of something or a refund of some fraction of the amount paid.
Depends on how you look at it,any product or service may make up the price in order to cushion the discount or commission to be given.In short,the price will be reduced after such.
2.I can't understand what you mean "inclyded",if you are referring to included?A unit price is an quantity of a good worth in terms of dollar and cent