A: that's bullshit.
B: that's bullshit.
I am a MEXT scholar at waseda and attending classes in the language school. They will break you up into level, so you will be placed with people of similar level, no matter where they come from. Even if others may be able to write more kanji than you, it will have little to no effect on your actual progress.
Most people here are korean and chinese. The chinese are excellent at writing kanji and will often correct the teachers. Those at my level can read them no better than I can. The koreans improve very quickly--their language is quite similar to Japanese, so you will see koreans make almost unthinkably fast progress if they really push themselves. Its a fact of life that one must simply accept and use as motivation--after all its better to see one's classmates progressing quickly than just piddling around.
Another thing (though it may be different at other schools): it is possible to attend classes here, and do well in them, without knowing how to write many kanji at all. I am completely indifferent to physically writing kanji and gave up the study a year and a half ago in favor of concentrating on other things (its not good bang for your buck since everyone does everything electronically these days). I can read about 1800 kanji and am in one of the upper level classes, but I can only write, I dunno, 300-500 without looking at my dictionary? Anyway, that has not hurt me whatsoever in my classes.