How can I (semi) automate a database export and import to a different location?

Well, I think you’ve already alluded to the answer. You need to script your database changes. And then run that script on the live database using phpMyAdmin or something like this command if you have terminal access:

mysql db_name < scripted_changes.sql

If, however, you’ve referring to CONTENT changes then that’s a different thing all together. eg If you edit a post on your dev site and want that post change to be applied to your live site, or if you’ve added and activated a plugin on your devsite. If this is what you want, I am sure there are solutions, but I would recommend you look at your workflow to see if this is necessary.