Possible Clues:

• Static home market raised nervous reaction
• Stiff or unyielding
• A stencil that's flexible alongside one that's rigid
• Cite snail (anag)
• International clients in trouble must accept answer lacking flexibility
• Opposite of flexible
• Not giving in, ruined castle defends island
• Awfully nice, a list difficult to change
• Iodine -- it cleans round the bend, like starch?
• Being the one whose turn it is, I castle desperately, having limited freedom to move