Personally I don't think Airbnb is suitable for long term bookings. You will really need to have proper checks in place for these ie landlord references, credit checks, tenancy contracts.
Of course you should be reporting this guest to the authorities for using your address fradulently.
I make it clear to all my guests who are moving to my area that they can't use my address for identity purposes.
How was a guest able to import huge quantities of goods and store them in your freezer without you noticing - are you hosting remotely.
Having had two problem guests in succession, can I ask what checks you are making before you accept your guests? Do you require photo ID? Do you ask them about plans for their stay? etc
I noticed you left a positive review for a problem recent guest, who you then went on to leave a more comprehensive, honest review, once they complained on their review.
Please leave an honest review for the Nigerian guest, you can always respond to theirs if it is inaccurate - but a word of advice, please stick to the facts, take out the emotion and make it much shorter than the one you left for your recent messy female guest.