When I look back at your first images, you are revolving some of your cuts where the edge if the metal is not "square". This is a machining process that causes angled edges in the flat pattern.
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Where and extrude cut takes forming into consideration
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Therefore, you want to be very coginzant of the operation you ware planning to use. You may even need both operations to leave the additional material in case you need to machine features at the mill rather than the flat fabrication.
As for ripping a seam in the 1st feature (revolve), the sketched rip goes long the thickness of the material (intuative, huh!)...
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So the unbend as the next feature is of the basic raw material. I turned off the relief option.
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I can test the unbend at any point:
