Yes. The ancient Churches which the Apostle Paul planted throughout Asia minor, the Balkans, and Greece are still in existence. The Church at Thessilonica, a recipient of two of the Apostles letters,...
I do not know for sure yet. However my 1st impression is 7 due to the interpretation of the book of Revelation that could be incorrect. They are the seven churches in Revelation.
Opinion.
Thirteen epistles have been attributed to Paul. Only seven Pauline epistles are widely considered by biblical scholars to be genuine, and of these five have been shown by computer analysis...