Android - Is it possible to set up a Google account for Gmail only?

I found a workaround for my problem that works splendidly.

After having installed the latest version of the Gmail App, I have discovered that when I go to Settings > Account > Add account, I can configure a generic email address (i.e. not necessarily a Gmail one) to be used with the said App. It supports both IMAP and POP3 protocols.

(sorry for the Italian, but it should be understandable nonetheless).

I suppose that this feature was meant to use email addresses from other providers inside the Gmail App, but it will accept any email configuration, even a Gmail one.

So I selected IMAP for my second and third email addresses, and now I can access those accounts just for Gmail; this way they won't be able to get in they way on other Apps.

On Google Help Center I have found the settings required to configure an IMAP account on an external client, which I have used. I'm reporting them here for completeness.

To configure the 'Email' app on an Android device for access to Gmail, just follow the steps below:

1. Enable IMAP in your Gmail settings.
2. Open the Email application.
3. Tap Menu and the Settings
4. In the top corner, tap  select Next to get started with setup.
5. Enter your full Gmail address and password, then select Next.
6. On the next screen, you can give the account a nickname and choose the name to display on your outgoing messages. Tap Done.

And you're done. You can verify your settings from the Inbox view by tapping Menu, select Account and then scroll to Server settings.

Incoming settings
IMAP server: imap.gmail.com
Port: 993
Security type: SSL (always)

Outgoing settings
SMTP server: smtp.gmail.com
Port: 465
Security type: SSL (always)

Now that your account is set up, learn how actions in your client sync with Gmail.

While you add the Google account or even afterwards (from account settings), you can select the content and services to sync. You can select only Gmail, leaving alone all the other services you don't want like Google+, drive, sheets, docs etc.

There's no need to setup a third party email client. All (most) Google apps are aware of this functionality and will work correctly.