If would be great if I could edit a text box in multiple pages at the same time, by giving it a special ID, if the same ID is used in any landing pages, the content would be dynamic and if I changed it on one page all of the pages with that ID would change the same text box.
This is a great idea, and it actually ties in very closely with another idea that was brought forward by the community. In the future, we plan on releasing a more robust way to create/move content across all of your Unbounce pages. This would come in the form of a global content/asset manager, but how it would be deployed is still to be determined.
If you have a moment, I would also consider voting on a similar topic in our community to increase the visibility towards this idea:
Thanks again for sharing this idea, Scott!