Hi @Thomas
We cannot provide legal advice here. If you wish to correct information you provided to BAMF, then you have to contact BAMF. I do not know whether there is a fine but it may affect the credibility of other information you provided.
A person is not deported solely because they have had to correct information they provided. A person can be deported if their asylum application is rejected and they do not have the right to remain in Germany.
For anything further on this, I recommend you seek legal advice or contact refugee advice services ‘Flüchtlingssozialberatung’ or the asylum procedure advice service ‘Asylverfahrensberatung’.
Best,
Éanna