Just regarding your 1st and 4th question, it isn’t the passport which gets listed in the SIS, it is the person. They collected biometric data from you and getting a new passport won’t help.
A criminal record is not an issue per se. There is no question asking to disclose it on the Schengen visa application form and no systematic exchange of criminal records between Schengen countries. Some other countries do ask you to disclose that or any previous visa refusal or removal and are stricter with this. The specifics would depend on the country in question but it seems you have at least been removed and that’s often relevant.
A ban on the other hand would obviously prevent you from entering the Schengen area (that’s the point). You can be banned for an immigration violation without being found guilty of a crime, this is not really linked to criminal records one way or the other. I believe there are some efforts underway to harmonise this further but member states have a lot of leeway in deciding whether to impose a ban or not. In some countries, even a longer overstay that gets your visa cancelled and/or detention and a police escort to your plane does not always results in a ban.
Based on the facts disclosed in your question, I agree with @phoog that your visa could and should have been extended but the German authorities are notorious for issuing bans very aggressively compared to other countries. If you have indeed been banned, applying for a Schengen visa is pointless, you first need to get the ban lifted to avoid an automatic refusal and only the country that issued the ban can lift it.
Whatever the case may be, you would certainly not be blacklisted forever for a mere overstay. An entry in the Schengen Information System last for three years by default but member states can renew it as they see fit. IIRC, a German ban is typically 10 years.
More generally, there is no global database of passports, criminal records or immigration history. Specific countries do have limited form of information exchange, often for intelligence purposes and not so much for regular immigration purposes. There are also databases of stolen documents and wanted persons (both at the EU level and through Interpol) but that does not seem relevant here.
The main concern is that you will often be asked to disclose this event and lying about it exposes you to many unpleasant consequences. Even without a database, there are many ways to be found out (stamps in a passport, contradicting yourself in an interview, being tipped off by an ex-boyfriend or jealous neighbour, etc.).
Credit:stackoverflow.com‘
5 Mar, 2024
5 Mar, 2024