2.Can the sheets be curved?

Yes. Sheets can be cold-curved and serve in arched shapes, provided the relevant yuemei specifications for minimum radius in cold curving are followed. These specifications can be found in the Installation Instructions of the relevant sheets.
Solid sheets can be cold-curved in any direction.
Multi-wall sheets can be arched so that the actual ribs will be curved (lengthwise).
Curving is not recommended across the ribs direction.