I think you could use the Linked Content feature as a workaround:
Create 2 masters: one with the elements that will never move (applied to your pages) and 1 with the elements that might change (based on first one). This master will not be applied but used as sources for linked content.
Open the Linked Content Tool, get the elements from this ghost master, and position them in a normal page (make sure "create links" is ON)
Then copy/paste in place those linked elements in all pages.
I recommend you lock the elements to prevent manual changes. Go preferences > General > uncheck "prevent locked objects selection". This will allow you to select an object and apply a style without he ability of moving it.
In your normal pages, apply an Object style based on a paragraph style to the elements you want to "highlight".
Now if you want to make changes, go to the "ghost" Master page and make the changes there. If you have to move the element (i.e. to the right), just extend the frame or play with indents: moving it would not have any effect. Update all links in the link panel. (Please note that in the Link panel, there's an Link Options sub-panel that you can find useful)
Note that I haven't tested this workaround due to lack of time. I don't like to post an answer without testing it before, but this would have been too long for a comment. So do not hesitate to report back if you experience trouble.
Another approach would be to link text content to an external file (such as Excel)