DO opens these files, at least tries, but ends up with error.
This is mine app is misconfigured, or just these files are tricky to handle?
Additional parts like zip.002 are in same folder.
Do I really need that, I just want to open archive and see contents inside.
7z allows doing so, without any additional joins.
Splitting zip files in that way is non-standard, at least. You'll need to join the parts back together before they can be accessed as a zip archive.
We support simple .001, .002 splitting for actual 7z archives, since that is the standard way to split those, but not for zip, since it isn't.
The standard way to split zip archives leaves you with a .zip file as the first part, and then .z01, .z02, etc. files for the rest of the parts. Proper split zip archives are also not simply split up versions of the whole archive; each part has its own extra header with information about it. (OTOH, split 7z archives are simply split up versions of the full archive, the same as if you used a split or join tool that has no knowledge of 7z or other archive formats.)