In my opinion everyone cheats at this game, myself included.
There are different levels of cheating though. Like when you go on trial for murder, it's not just murder. it's a specific kind that defines your intentions more clearly.
All of the following, in my opinion is cheating, but in the order of minor to serious offenses.
Using The Brady Guide. (can disadvantaging yourself be considered cheating?)
Asking someone how to do a quest without figuring it out yourself.
Looking up info about the game on sites like Somepage, or qcdn.
Using a Parser.
Power leveling.
Using tools like TParty, Draw Distance and Blood Pact timer for windower.
Using extended Macro lines for windower.
Buying Gil
Warp Hax, speed hax
Claim Hax
Crazy shit like "I can't die" Hax.
You'll notice I left using windower off the list. I believe you can use windower and still give yourself no further advantage. I think SE is completely wrong about it and in my mind it does not qualify as cheating.
For the most part, everyone agree's war/flee/claim tools are cheating. That is not in question. Some people believe buying gil is not cheating just a time saver and the division officially begins here. There is still a solid majority that believes this is cheating.
Then we have the windower plug-ins. These help you perform better by granting information you shouldn't have. There are some people that are adamant that these are cheating, but they are generally accepted among the better part of the community.
Even the ones that reject windower would never have the slightest word against fan sites filled with volumes of info about every quest, npc or item you would ever encounter in FFXI. Noone considers this cheating because everyone does it, and it's not against EULA. It matters not, even though I use the sites myself, I still consider it cheating because it's info not readily available to all players. Like someone that plays on PS2 and has a broken computer. They are automaticlly at a disadvantage because they can't see this info and they have to either beg for help, or figure it out alone.
We all cheat. The question is how much.
I use fan sites and windower with no plug-ins and no extra macro lines. I have been known to power level from time to time.
That's all my skeletons.