Is Disabling Virus scanner integration with Outlook is it's a good practice to do?
Yes as disabling will gives you less headache than leaving it on. So that that most of time it is advised to disable it when you are experiencing some issues like:
Built-in Outlook security not allows code to be executable when viewing email in reading pane. So it's not possible to get infected by a virus by opening mail itself. To get infected you have to double click on the virus attachments for it to be executable.
As a safety provision, Outlook doesn't permit you to double click on attachments that contain a virus. In case you have additional attachment that carries a virus, the on-access scanner of your virus scanner will kick in and restrict it from being executed.
The on-access scanner uses the equivalent anti-virus definition as scanner integrates with Outlook, having the integration will not bring an exact layer of security and thus you can disable this form of integration.
How to disable integration depends on virus scanner solution. Some security suits have a control panel on their own were disabling of component is possible but it's not enough as it may disable the functioning, it won't disable its integration. Some they display themselves as Outlook add-in, so you can disable it by Outlook. This usually could result in security alerts by virus scanner and windows if virus scanner notifies windows about security alerts.
To counter virus scanner solution the best way is uninstall virus scanner completely and then reinstall virus scanner again but at the time of setup make sure that you don't specify to install mail scanning component. The documentation of virus scanner solution can gives you more information about how to install only certain component if it is not clear to you.
If virus scanner doesn't permits to disable its Outlook integration or if it not provides you an unprotected alerts, then you can use free alternative Microsoft security essentials.