Google states:
You must provide a developer email when you create your developer account; here are some tips about which email to use:
Because you will receive important emails about your extension or you may want to delete one of your accounts, we suggest using a new email account just for publishing your Chrome Web Store items.
What does "wanting to delete one of your accounts" mean? Is this specific for the developer account or do they refer to the Google account?
Here they state:
First you will need to register as a Chrome Web Store developer. We suggest using a new account just for your item instead of your personal account.
What does a "new account just for your item mean"? Does this mean a separate account for each extension I publish? Again, what type of account? Can a Google account hold multiple developer accounts so the reference is to the developer account or do they mean separate Google accounts per item?