Having followed your posts a little there is no question that you would be a very hard study student for them and it would take all their effort to stick it out. They would need to be very intelligent and confidently know their beliefs inside and out. You would be proving to be a test on anyone who took on the challenge.
It wouldn't be surprising if your instructer has had enough and has found it too draining, if not a little bit disheartening. The best way to deal with that is to get out of the study somehow. Nine months is not a long time and probably too early to be dropping a study, if he didn't think you were worth continuing with he wouldn't have handed you over to another instructor. It is probably likely that your new instructer will be more knowledeable than him so it would be interesting if you had one or two studies with him.
From what I know, it was appropriate for a study instructer to advise the study that they didn't feel they were progressing and getting anywhere and spend the whole of the study discussing what you were looking for, what you had already recieved from the study so far and what you were expecting from future studies. A change of book may also be suggested.
I really think Black Sheep's comments are right on target.
You didn't mention whether your instructer had kids but as you mentioned his wife, I assume not. It could be that he is moving to the other congregation so that they both can learn the language better with the hope of being posted overseas in the future. They do encourage others to learn another language with this in mind and he may have been specifically asked.
You would have given him a lot to think about and only time will tell how he has taken it.
In regards to his comments
"1 Cor 2:14 which says "But a physical man does not receive the things of the spirit of God, for they are foolishness to him; and he cannot get to know [them], because they are examined spiritually."
As you would already know they use this as an entrapement. That is they want you to think that you aren't being spiritual and therefore don't understand and if you were then you would accept it unquestionably. Sprituality does not defy logic or understanding, they can go hand in hand. They also make it seem as if there are some secrets that can only be unlocked and understood if we are more spiritual but this doesn't mean that we will understand doctrines and beliefs because of spirituality. It is our understanding of God himself and an appreciation that he is the almighty in all things that we grow to appreciate as we become more spiritual.