Is there a way to set a different password for the API key than the main constant contact account? Porblem is whenever that password is changed, it affects the key access and creates an error. Then we need to update the code to reflect the new password. Ideally we want to set a different password for the key.
Also, we've noticed that sometimes we get locked out of the account. Why does that happen?
As of right now there is only one password and username per account. However you can use oAuth in your integration so that you wouldnt need to supply your password which would resolve your issue. You can read more about the oAuth flow here.
To answer your second question, it's likely that you're being locked out of the account when you update your password and your API integration continues to try to use the old one. We disable access to your account after 6 failed attempts through the API and the UI.