Hi @screnshaw -
For #1, “Compare Object with Account Version” does the comparison with the object in the account you have selected in the Project Settings. In order to compare against another account, you’ll need to change the default account. I can see why that can be a hassle, so I just told our PM that we should add a second action where you are prompted for the account you want to compare against.
For #2, SDF allows you to import the first 100 instances of a custom record into your project. This is to be used when those instances are not data, but instead metadata. For example: they are acting like a Custom List but with more properties. Once you import them to your project you should be able to deploy them to the other account. If the instances are data (hundreds and hundreds), then you’ll need to use CSV.