Referring to the first screenshot, when you execute the workflow and it goes into a Paused state because your workflow is not configured to end. To move the workflow to a Finished state you need to have an End activity connected to the two transitions.
Enable but do not execute
When you configure an activity with this option the workflow will execute until this activity. In other words, the current activity will not be executed and the workflow will keep the temporary worktable of previous activity intact for data review.
We use this option mostly to review the contents of output coming from previous activity.
Do not enable
When you select this option on an activity, it is same as the activity doesn't exist in the workflow. Even if you have additional activities connected to the disabled activity, the workflow will discard all of them and will run up to the disabled activity before moving to a Finished state.
It will then purge the temporary worktables created in the background.
There is no way to skip an activity in a workflow. If you don't want to execute an activity but execute the remaining workflow, you will have to delete the activity from the workflow or disconnect it from the workflow transition and select Do not enable.