1) Something is wrong with this. Either he meant "I am not saying that..." as you suggest or "It is not that..."
This is a mistake. He probably began typing one thing and later edited it. It's not a permissible omission.
2) No. "Should someone... so desire" is the proper grammar. It means if someone from distribution desires to participate.
3) He is saying he can not commit to anything until he gets the answers he needs.
Student or Learner