If you set up 2-step verification, you have to log in to your account using your email and password, and then a generated code that is sent to your cell phone. Most likely, if someone hacks your account, they won't have access to your cell phone, so your account will be safe.
Here are instructions on how to set up 2-step verification:
**I would only recommend doing this if you always have your cell phone with you. You can also print out some codes that you can keep in your wallet in case you don't have access to your phone. If you are using your own personal computer, you can make it so it doesn't ask you for the code each time you log in.
If someone does hack your account, and is able to gain access, the first thing you want to do is change your password. To change your @seq.org password (for Google, SL, IC, etc.), go to this website.