What could help you is to use the Find functionality by CTRL + F and search for ‘;’. If you only check the ‘Page widget name, class and style properties’ checkbox this should give you a good overview.
This only works if you’ve used the semicolon to end your css declarations.
Don't know if it still works, but I created a tool for this type of situation:
https://github.com/JelteMX/mendix-project-stylereporter
What this does is checkout your project using the ModelSDK, go through áll pages, snippets and layouts and will create an Excel file with an overview. One of the columns will tell you which element has inline styling. Also, there is an overview of all class names used in the project.
That should at least solve your problem of finding all elements. Let me know if you run into problems, I might be able to debug this tool (I haven't touched it in a long time, so I might have to update the ModelSDK library)
As far as I'm aware of it: No
only options I do see:
Both are not that inviting though
Good luck!