For example, could you save the login/password info in the browser’s password save section and thereby bypass the login steps in the script.
The short answer is, it depends. If the password filling relies on the actual browser cache, then this will not work for IE or the iMacros Browser since the iDrone regularly purges the cache. There is currently no way to prevent this. If the password filling relies on built-in browser password storage, such as with Firefox or Chrome, then this should work fine.
Keep in mind that this is not an officially supported feature, and that you can use iMacros password encryption as an official alternative.