How to contact blizzard support without login to the account

If I'm understanding your question properly, in order to have two Heart of the Swarm licenses you need two Wings of Liberty licenses.

Since Heart of the Swarm is not a stand alone expansion, you need to have all the prerequisite games in order to play it (each copy).

You can see for example, on this Cataclysm box art for World of Warcraft, that it requires "Wrath of the Lich King to play". Wotlk says it requires TBC, and TBC requires the base game. It is expansions all the way down. This trend stands true for all Blizzard games to date, as they don't release stand alone expansions.

No. Think about it. Since you have to use an email address to log in, how would the login server ever know what account to log you into?

You'll just need to create a new email address. Also, from Blizzard's Terms of Service:

Ownership/Selling of the Account or Virtual Items.

Blizzard does not recognize the transfer of Accounts. You may not purchase, sell, gift or trade any Account, or offer to purchase, sell, gift or trade any Account, and any such attempt shall be null and void. Blizzard owns, has licensed, or otherwise has rights to all of the content that appears in the Program. You agree that you have no right or title in or to any such content, including the virtual goods or currency appearing or originating in the Game, or any other attributes associated with the Account or stored on the Service. Blizzard does not recognize any virtual property transfers executed outside of the Game or the purported sale, gift or trade in the "real world" of anything related to the Game. Accordingly, you may not sell items for "real" money or otherwise exchange items for value outside of the Game.