New Post: How to deploy mutli project solution using BTDF

Are CallOrchestration and HelloWorld both BizTalk applications? If it's all one application, then yes, you can deploy any number of DLL's from one .btdfproj. Add it to an Orchestrations ItemGroup.

To your second question, the Deployment Framework always processes entire BizTalk applications, not individual artifacts within an application. If you want to deploy just a specific DLL, you'll have to handle it another way.

Thanks,
Tom