[wilsonng]

Not sure about the first one.

But the second will be easier.

Select the menu bar Omnifocus > Preferences.

Click on the "Data" icon at the top of the Preferences window.

The first item will be what you are looking for.

Clean Up Inbox items which have: [popup menu]

Select the popup menu and choose "Both a Project and a Context"

When you are in Planning mode (Command-1), you can look at your Inbox and you will see all tasks that do not have a project and/or context assigned to it.

When you have assigned both a context and a project to the task item, it will disappear from your Inbox and move to the appropriate project and context.