the problem seems to occur due to the in accuracy of the translation
See picture showing You the difference in thickness
You easily can repair this using the Optimize function of Inspect Tools
After repairing You can create Your sheet metal part using the "Thin Part To Sheet Metal" button in ordered mode. Sync will not do this in Yopur case, since there seems to be connections radius to radius which arenot working in sync but do it in ordered.
See flatten pattern
Yes but as said before, You need not changing anything here. Still run the Optimize command from Inspect tab.
This is all You have to do and then change it to Sheet Metal in Ordered!