drupal 4.8: need to decouple node validation from forms

I am working on node_import module. I encounter the issue that I need to validate nodes I wish to import, but the only way to do this is to call node_validate which calls form_set_error as a means of registering errors. hook_validate follows a similar approach. If we could decouple the validation of nodes from node error reporting mechanism, I could have flexibility in validating the nodes I create outside of the form system. Similarly I would like to create a workflow / process to change 1 node to one of another type. Again same issue.
Thanks