Will importing a View that already exists merge with what isn't there in Drupal 7?
WHOA STOP. haha

Install the Features module and create a feature with this View in it and deploy (git/sftp) the Feature up to production. then revert feature and boom. latest view is there. 


Download, enable Features on Dev
Create a new Feature
Add your View to this Feature
Save the exported feature into your file system for Drupal
Enable on Dev and verify that it is in the default state (it should be)
Download, enable Features on Prod (or use git to merge you dev branch into prod)
Place this new Feature onto prod (either using git or SFTP)
Enable this feature on prod. Since you have the View already, it will probably be Overridden. You can simply view differences (using Diff module) or revert it.


Note: I highly recommend a staging environment between development and production so you can test these types of reverts and adjustments prior to making changes on a production site.