Interesting. Was the archangel Gabriel the source of the koran?
1) Is Islam another gospel? Yep
2) Is Gabriel an Angel? Yep
3) Can an Angel of God (not a fallen Angel) lie? Nope.
Answer is NO.
Paul is supposing an impossible case...with a metaphor. He is basically saying: It doesn't matter WHO it is...if they teach something contrary to THIS Gospel...let them be devoted to the direst of woes.
No.
The archangel Baalzebubb was.
No nor did he bring the book of Mormon. It is interesting the Bible wasn't given to us by Angel's, but directly by God. II Peter 1:21" For the prophecy came not in old time by the will of man: but holy men of God spake as they were moved by the Holy Ghost."
Many times the Bible tells us to have discernment because "For such are false apostles, deceitful workers, transforming themselves into the apostles of Christ. And no marvel; for Satan himself is transformed into an angel of light. Therefore it is no great thing if his ministers also be transformed as the ministers of righteousness; whose end shall be according to their works." II Corinthians 11:13-15. I cannot think of a passage in the Bible where an angel brings us scripture. They bring messages, but usually the Bible will say that the word of the Lord came unto whoever God is using the write the scripture. Search included for study purposes:
http://www.biblegateway.com/keyword/?search=the%20word%20of%20the%20lord&version1=KJV&searchtype=all&limit=none&wholewordsonly=no
John 1:1 "In the beginning was the Word, and the Word was with God, and the Word was God." I get my scripture from Jesus who loved me enough to personally send and be the Word; not from an angel.