What evidence do we have for or against Paul ever having personally met Christ?

Answer 1

First we have to make clear than Pablo was called Saul but His name was changed to Pablo after His conversion to Christianity.
The moment when Saul(Pablo)personally met Christ is mentioned in the book of Acts chapter 9 verses 3 tr ought 6.
9:3As he neared Damascus on his journey,suddenly a light from Heaven flashed around him.
9:4He fell to the ground and heard a voice say to him,"
Saul,Saul,why do you persecute me?"
9:5"Who are you,Lord?"Saul asked."I am Jesus,whom you are persecuting,"He replied.
9:6Now get up and go into the city,and you will told what you must do."

Answer 2

This was Paul's first encounter with the risen Christ
Act 9:3 And as he journeyed, he came near Damascus: and suddenly there shined round about him a light from heaven:
Act 9:4 And he fell to the earth, and heard a voice saying unto him, Saul, Saul, why persecutest thou me?
Act 9:5 And he said, Who art thou, Lord? And the Lord said, I am Jesus whom thou persecutest: it is hard for thee to kick against the pricks.
Act 9:6 And he trembling and astonished said, Lord, what wilt thou have me to do? And the Lord said unto him, Arise, and go into the city, and it shall be told thee what thou must do.

Answer 3

Only Paul's word. And considering the results of his efforts after supposedly meeting Christ; I don't believe him.

Answer 4

Same evidence as anyone else - their word & their actions.