Apple Store Purchase history Knowing I can't get rid of the purchase history at all, I've removed payment details and changed the email address from one@whatever.com to a fake one. 

Then started using a new one, two@whatever.com. I have purchased several apps.

I was wondering, if I add the first email address now (one@whatever.com) as a secondary e-mail address to this two@whatever.com Apple Store account, so I could log into Apple Store with that aswell, would the account show purchases I've initially made on the previous Apple Store account - one@whatever.com?
You cannot add any email address that is in use for any other Apple ID. 

You cannot transfer purchases from one account to another.

You could set up Family Sharing - but all that would do would be re-expose the purchase history to both accounts.