Good question. In principle, yes, but there are some differences in the structure of organizational and personal vaults. I’m not sure if these will create problems during import of a JSON formatted export.
If your vault does not contain any Card or Identity type items (i.e., only Login and Secure Note items), then an export in CSV format may be more robust — i.e., it would be straightforward to condition the exported CSV so that it can be imported into a personal vault (it seems that all you’d have to do is to delete the column titled collections, and add an empty column with the title favorite). Other than not exporting Card or Identity items, additional repercussions of switching from JSON to CSV export would be that all custom fields would be converted to fields of the “Text” type, and that URI match detection settings will be lost.
An organizational vault can be purged, but please note this FAQ answer.