I wanted to know whether the Samsung Galaxy S4 will run every app from the play store or not? I had done a lot of googling but failed to find an answer.
No there are not all compatible. When you watching an application on Google play ( from your device ) if you cannot find the button for installing that app, that means that your device is not supported by that application. Also if you visit that application page on Google play desktop site, and your device is listed in your account than a message will appear in browser that says that specific application is not compatible with your device.