> 1. Don't use personal gmail accounts for your business.
A good practice but won't help with this issue. Google has a history of banning business (admin/paying) accounts when it thinks that some user (under that business domain) has an unrelated personal account that was banned.
There have been stories here on HN describing how a small startup lost its Google Play account because one of their employees had their personal account banned for a terms of service violation. Then Google viewed that same person having an user account underneath the business account as ban evasion. In a puzzling move Google then proceeded to close the whole business account, so lots of collateral damage.
1. Don't use personal gmail accounts for your business.
2. Don't mix different business units on the same account. (Your 5-year old adsense page you forgot about probably isn't compliant anymore).
3. If your personal account gets banned, hire someone whose job it is to manage your business google accounts and don't touch them.