Yes, you can have two accounts on the same laptop and they can have the same email address.
The only problem with having more than one Skype name with the same email address is if you ever forget one of the passwords, the automatic form for recovering your password may take you to the wrong account, or not. There's a 50/50 chance.
If you have a second email address available, I recommend using a different email for the second Skype name. If you don't have a second email address available, make sure you don't forget your password(s). 
