Is there a function: forcibly clear the "priority option" before the application style.

What the others have already said.

BTW: It would be better to delete the unnecessary indent to the here characters and the partially superfluous spaces. These are just annoying and are not needed at all.

This is common when importing from Word documents; a general solution is to NOT use any spot formatting in the source document, and thoroughly map all imported styles at the time of Place/import, using the Import Options menu.

It is rare not to need some style cleanup after an import unless the source document formatting is perfect and the import mapping is complete.

Alt + click on the style will clear all overrides - for the selected text / Paragraph. 

If you want to clear all overrides globally in the document - for a particular style - you need to perform Find&Change this style on itself - you leave Find / Change fields EMPTY - just style on itself.