It doesn't take a lot to figure out how well catechized someone was. After you get through the gobbledy gook of "I grew up in a Catholic family of umpteen kids and we went to mass every week and I went to catechism and I was abused (physically emotionally and/or sexually) by the (nun, priest, janitor)I start looking for what specific doctrinal points they actually had a problem with.
The nun was easy. She wrote:
How many times do we need to be saved? If I receive Jesus Christ at communion time, what happens to Him during the week that I have to go back and receive Him again? And why should I drink blood when blood is forbidden before the Law (Genesis 9:4); Under the law (Lev. 17:14); and in New Testament times (Acts 15:29; 21:25)? The Bible says Blood is off limits, we are to abstain from blood, but in the Catholic church we are to drink it!
My 8 year old gets the difference between actual blood and the divine Body and Blood of Jesus Christ that we receive in the Holy Eucharist. Readers can check it for themselves at the Catechism of the Catholic Church on this section regarding the Holy Eucharist.
Brother Vadavan is even more vague about his doctrinal differences. He apparently wrote a book about it, but I couldn't find it online or on Amazon or Google Books.