Use bookmarks for each service using /u/0 or /u/1 to use the default account or the second account.
Some web browsers allow to have several users profiles. Use one profile for one service, and another profile for the other service
Use two different web browsers, i.e. Chrome and Firefox. Use one web browser for one service and the other for the ...
From Google Account Help:
Delete your Gmail service
If you don't want your Gmail address and emails anymore, you can remove them from your Google Account. Deleting them won't delete your entire Google Account.
If you use Gmail through your work, school, or other group, contact your administrator.
Before deleting your Gmail ...
Remove the Gmail service from your Google Account. In order to be able to do this you will need an email address that is not used as the primary or alternative email address of another Google Account. For step by step instructions please read the official help article:
Delete your Gmail service
Can I re-create deleted Gmail accounts?
Need to ...
To do A and B there are two paths
Add the script code to a Google Apps Script project owned by you (the same account used to run the script should be its owner)
Create an add-on a ask Google to verify your script.
The Google Account official support is https://support.google.com/account and the official forum is https://support.google.com/account/community, the Twitter accounts and other social media are listed in https://www.google.com/press/blog-social-directory.html
Anyway, Google doesn't require any proof about the name set for the account, so you could use any ...
Short answer: No.
Google Brand Accounts are accessed through a Google Account- By logging out of your account will not log out other users from their accounts, and will not block them to access the Brand Account.
If you are the owner of the Brand Account you could add/remove other accounts to help manage it.
There is no login/logout for Brand ...
Google has a tool to do an account security checkup
It will show a list of security checkpoints. Each of them will contain a list of items to be reviewed by you including a link to a help article that explain each risk.
Suspicious access to my Gmail account from "Authorized Application"
Regarding the "Can't reach this page", the most straight forward solution is to clear the cookies and delete the cache of your web browser. Then sign in again to your account.
Regarding being lock out from time to time, for security reasons, Google will ask to sign-in again in the web browser every certain time.
"Perhaps the ability to sign out of a single account has been removed?"
I am afraid you are correct.
It has nothing to do with the kind of the operating system (Mac, Windows, Linux etc) you use.
It also has nothing to do with the browser you use (being Chrome, FireFox, Safari etc).
It is ALL about the browser you are logged into from.
As per the ...
Can you give any more details?
In general, there is usually more than one way to access email from an email provider. If you have lost your password, you can use a password reset function from the website version of your email.
It's purposely meant to be a little difficult, so it's harder for people like abusive users to get access to accounts.