Split pane vs Action for multilple selection

I'm bulding a User interface that the user has a split pane with a list and the detail of the selected item in the right. I chose to use these approach because the user could see the important information before take some actions and he has a lot of information to check early. In these context is also common that the user take actions for multiple items in the same time.

The user can see the details of the selection and there, he can see a lot of important documents and also can select a button in the top right to take action.

I was wondering if would be ok or a problem if the UI offered multiple selection by checkboxes and repeat the common actions to the selected items and also allow the navigation between items, so the user could select any item and see the details even if it was not checked.

But the user would be blocked to take action in the right pane because it only concerns to the selected items.

Wireframes below:

FIRST SCENARIO: Normal selection

Screen 1: User access split pane with an selected item. Ther he can navigate between documents and take actions in the right menu

Screen 2: User access the menu

Screen 3: User access the first action, which is navigate to the second level to analyze deeper

SECOND SCENARIO: Multiple selection

Screen 4: User selects many items and can take the common actions to the checked items in the buttons that appear above the list.

Thee user still has the possibility to navigate between all the items in the list and see the content but is not allowed anymore to take individual actions ( in the menu of the top right) because the menu in this context becomes disabled.

I researched behaviors like these in other platforms and did not find any. My question is: Do you think this behavior is ok to the user? Any suggestions?

Gmail, for instance, has a possibility to check a lot of items, and take for the selected item or the checked items.

Nevertheless, i think my case is different, because one of the possible actions for my UI is the user navigate to a second level to analyze the documents and in a structured way. Gmail do not has this kind of navigation. The actions remais in the same view.

Bellow in the two images of Gmail you can see that the user can take actions for multiple items. But also can take actions for the selected item