garment specification sheet
To solve the issue of the zip, hook and button breaking, I feel you should stick to a simpler design by either just using a zip. Potentially they could alter the design but putting in an elastic fabric tie belt instead of using a zip that has the risk of breaking.
To overcome the stripes from ripping, a lining should be inserted into the trousers to prevent this problem. If not this means that’s a thicker material should be considered.
In bulk production I have concerns that the stripes on the side of the trousers will come out uneven. Therefore, I feel this problem should be overcome by the stripes being graphically printed onto the trousers. This also will take less time for the product to be made and less stitching needs to be done.