How to become famous and write lemons.

[NekoDramon]

What is the meaning of original?
How to be in between original and not too original? Any examples?

Well, he gave examples there. And it's easy to confuse the terms. I think he meant "Be creative" in point 4, but "Don't use too many self-created characters or plot elements at once" in point 5.
So a creative couple makes people interested, but if I have to study 8 new DigiDestined and their (made-up or fan-created) Digimon AND the customized timeline the lemon is set in, it's too much.

How long should a lemon be? No offense, sometimes lemons less than 5 pages are better than 100 pages.

A plotless lemon most likely can consist of less than 5 pages and still be good. But a good bunch of people value plot development more than a story that consists only of a lemon scene. And to be honest, I haven't yet read a lemon less than ~4-5 pages with nice plot development AND a good lemon scene.

What type of fonts can attract readers? Normal Times Romance or funny but readable fonts?

You may have noticed it so far: I'm a reader, no writer. And my opinion as a reader is: If I have to squint my eyes, I hit the back button. And concerning custom fonts: If I don't have your specific funny font installed, I won't see it. And so far, a funny font didn't really made me read a lemon I wouldn't have read anyway.

Does it necessary to put all disclaimer for all characters used in the lemon, for e.g. Gallon, Spider-Man and etc.?

*shrug* I'm no lawyer or author, but a hint on who owns/created the character won't hurt I guess.

How to make a lemon more interesting to read, for e.g. pictures, music and etc?

Once again I can only speak for myself. Pictures... don't hurt unless they're big and useless. But I read lemons to form my own picture in my head, and sometimes a "helpful illustration" can destroy that picture. And Music in Documents or HTML pages... please no... I have my own music running in the background, and when Mozart or System of a Down (don't ask... my music taste is... unusual) suddenly mix with MIDI tunes, I eliminate the source of the music with ALT-F4.

All of this is only what I personally like/dislike. Others may (and most likely will) disagree with me.

EDIT: Blitz: Witty remark, almost made me chuckle. Let's just take the liberty and add "PRACTICE MAKES PERFECT" to his list, okay?