1) If you are referring to "Link DTM embed code" option in Adobe Launch, it's only applicable to the production environment. Yet you can have two scripts in your staging environment - DTM script and the Launch script - and that won't cause any issues.
2) Yes, it would be just okay to have a single dev environment and a prod environment.
1) If you are referring to "Link DTM embed code" option in Adobe Launch, it's only applicable to the production environment. Yet you can have two scripts in your staging environment - DTM script and the Launch script - and that won't cause any issues.
2) Yes, it would be just okay to have a single dev environment and a prod environment.
Just to clarifiy here. You can not run Launch and DTM on the same site at the same time. They both use and reference the _satellite object and will conflict with each other.