Actually, you should make it a practice to change your passwords periodically, and, where available, to use two-factor authentication (via text message to a cell phone, or using some other method).
The fact that changing your password triggered the overall mess with your OBi doesn't mean that you will have the same experience next time. At most, all you will need to do is to log into your Google Voice account in your browser, log into OBiTALK in another browser tab, click on your Google Voice SP on OBiTALK, and re-authorize it.