Can this cart be used on concrete floors without damaging them?

Cart-to-floor compatibility depends on wheel type, which isn't specified in the product data. Test-roll on your shop surface before committing to regular use — if wheels stick or catch, a mat underneath prevents concrete scuff.

Is assembly required, or does it ship ready to use?

Assembly status isn't confirmed. Assume basic hand assembly — inspect all components and fasteners when it arrives, and pre-check that layers lock or seat properly before loading tools.

What's the weight capacity per layer?

Weight limits aren't specified in the product data. Load conservatively with hand tools and light supplies first, then add incrementally — if the cart feels unstable or flexes under weight, redistribute the load or use a heavier-duty model.