When I work from CAD exports, in edit mode I usually do: “select all - tris to quads followed by delete/dissolve limited”. For simple sheet metal parts like this I also make sure to suppress any small regular bevels (I keep chamfers) prior to export. Especially deburr bevels you might have added to make in-software renders look better. Such stuff on easy models are best to remake in Blender or just use the bevel node (Cycles). Complex bevels (likely not used on sheet metal parts) like face bevels, conical bevels, varying bevels, asymmetric bevels, and complex continuous bevels - these are hard to impossible to get (at least accurately) in Blender.
Using object coords (not UV space), normal maps that depict complete randomness like this one where up vs down doesn’t matter, works good enough as normal maps. This won’t “work” where up vs down matters, such as pressed diamond pattern.
Normal maps are better, more efficient, can hold more information, depicts angles accurately, and suffer less resolution problems. But they are mostly meant for game assets with proper UVs laid out, where the normals are either painted into the texture or baked from a high resolution mesh. Bump maps are way more forgiving to handle, as they don’t require UVs, and they also work with box mapping/triplanar mapping techniques in that dark is low, bright is high, and orientation doesn’t matter. It’s heavier to calculate for the renderer, because the normal modification have to be derived from the texture whereas in a normal map it just looks it up.
If you have problems with normals due to weird topology, sometimes you can get away with it using a Weighted Normal modifier or even just set annoying flat faces with erroneous shading to be flat shaded. Otherwise, or when working with curved surfaces, you’re gonna spend a lot of time cleaning up the mesh. There is no B-Rep rendering in Blender.