What does Misfile mean?

transitive verb. : to file (something, such as a document) in the wrong place … the inaccessibility of information that is being typed, is in the mail, ha...

Can I hold both H1 and H4?

Yes. H1-B is valid till date of expiry or until H4 application is approved. When applying for change of status via I-539 , you can also request for future...