[quote=@Letter Bee]
[@AndyC], Sorry for the double-post, but are there any forbidden 'High Concepts', such as 'Unhinged Lunatic' or 'Heir to a Throne'?
[/quote]

They're all on the table. Though "Heir to a Throne" would be the heir to a Periphery world or a corporation, rather than the heir to a Great House or the like.