I have one google email address, but multiple shopify stores. Can I add the google sales channel to each of my stores, but using the same google account?
Yes you can, however you will most likely get suspended if you have multiple website other then the following scenarios.
You are a manufacturer with multiple brands
You are a merchant targeting multiple countries
You are a marketplace
If for example you have multiple websites and 1 business entity, you will experience a suspension, which can happen at any time.
I’m just a person who has 3 separate brands: one selling clothes, one selling sauerkraut, and one selling stationery. Would this get me suspended?
In that case, that would be a reason for suspension yes, if you don’t fall under any of the 3 previously mentioned categories.
Consider merging all websites into 1