Re: Togashi's illness?
After digging a bit on web, I found some explanation as to Togashi's constant hiatus.
tl;dr Togashi is a lazy manga artist.
A few years ago there's a series of articles titled "the disappeared manga artist" that talks about manga artists that seems to stop drawing (the whole thing is in Japanese and I only found a Chinese translation one some Chinese site),and one of the articles talks about Togashi.
Long story short, Togashi is completely fine. The long hiatus is not cost by illness or anything. It's simply that Togashi doesn't want to devote his life completely to manga, and he wants to enjoy other aspects of life. In another word, Togashi is not a model manga artist.
Basically it started out during the end of Yu Yu hakashou. Because of the constant pressure from the editors of Jump to continue the story, Togashi has actually grew tired of drawing manga during that time. To the point that he feel sick just looking at rough drafts. Secondly the pressure of weekly releases has impacted his health considerably. Add to the fact that Togashi insists on working by himself without assistants to finish the final draft, the result is that Togashi wanted to quit drawing manga at that point.
After Yuyuhakashou ended Togashi went into a one year hiatus from drawing manga. His next work Level E would again be released on Jump, however it'd only be release on a monthly schedule.
There was a quote of Togashi somewhere that he doesn't want to die drawing manga, and insists on drawing only what he wants to draw.
So basically Togashi is not sick, he's just enjoying his life.
The article is title "消えたマンガ家", published on this magazine
http://ja.wikipedia.org/wiki/QuickJapan
by this person
http://ja.wikipedia.org/wiki/大泉実成
The column series was combined into a book in 1996
While this is before Hunter x Hunter starting serialization, I believe this is still relevant in understanding Togashi now.