You can try removing all the EV related entries in your System DSN tab (Administrative Tools > Data Sources), then restart the EV admin service which will recreate those entries. See if that clears those warnings.
I've seen deleting the temporary internet files fix folder structure issues in Archive Explorer. On one pc it looks fine, while another it does not. It's worth a shot.
When using collections, it's recommended to have at least 10% free drive space. This is for an retrieval reasons as well as exports of archives as DVS will be extracted to that partition as ARCHDVS files (though will only say temporarily).