This probably crosses the line on discussing cheating... But Neopetsisn't as popular as it was (and RIP, iDB), and I've *always* wondered on this topic. I've stopped playing as of about a year ago, but this bit of my curiosity lives.
Do any/some/many/most of the users with strong pets that do a ton in the past wars on Neopets use some sort of automated battling system? There are significant numbers of users with 10's of thousands of fights in each war. Yes, I'm sure many do all of their battles by hand while watching TV or some such. But it's ripe for automation.
------ Why I'm asking...:
It's much less likely I would be asking if I didn't know it can be done... It can, and I have.
I implemented automated battling a few years ago and used it very successfully in whatever war was a year and a half ago or so. To the tune of automating around 3000 wins. I won't say how I do it, but I can assure you that the BD's coding, which has never changed from its original form, makes it pretty straightforward.
And before you jump on me for my cheating ways, consider this: who did I really harm? I'm one person getting a few extra war prizes that I never sold. Your typical autobuyer does much more damage to the economy/etc. What did I gain? Numbers on my pet, yes... but there aren't rankings for those, really. More importantly I gained practice in the scripting language that I use for other useful things. In fact I used this work as the basis to get large amounts of data from another program for an college engineering project a few months later, and that only took a couple hours to whip up the solution for. I could go on, but I'll summarize this tangent as: Learning html/css, improving image-making skills, and later honing scripting skills are how Neopets has benefited me most.
I think you answered your own question. I've never scripted anything. I do admit that it would probably be useful in gathering data (legitimately) in certain circumstances, and I could see how practicing on a site like Neo could help you ease into it. However, my account's too old and valuable to me to jeopardize. I got near the highest score on TFR plot, but that was because there were win limits on all (?) of the steps. I will admit to making copious use of my F5 key, or clicking while doing something else.
I don't think anyone with a very strong pet would be stupid enough to admit publicly that they auto-battled, even on forums outside of Neopets, since they're usually not anonymous. I remember there was a scandal several years ago where several high-profile accounts (mostly top battlers) were frozen, and they claimed they'd done nothing wrong... Perhaps TNT did detect auto-battling? Or just suspected it? At any rate, several did eventually get their accounts back.
Depending on how you set up your program, it may not be detectable to TNT. I know there really are people who battle non-stop during plots (or claim to); one beat the top, "undefeatable" boss during TFR, but it took him into the next Neopian day (I think it took him close to 24 hours total), so he didn't get credit after all that effort. (I've seen the screenshots, and they seemed pretty legit. He at least had the weapons and stats to theoretically pull it off.)
Every few months TNT seems to be able to root out the autobuyers and hold them at bay (for a little bit); I tend to report people with hundreds of the cheapest codestones for sale on the assumption they've been autobuying (because it's not really profitable to do that manually; I figure TNT will be able to examine their activity and determine whether they are in fact autobuying). It's very noticeable when those accounts disappear and codestone prices drop several hundred NP in a few days. So I'm not sure how TNT detects them, though I've heard they're able to detect things like reloading a page at the exact same interval.
On who you harmed, I think you made it pretty clear. You netted yourself a little more prestige than the lot of users on Neopets. And while the only scoreboard I'm aware of for battlers is for 1-Player Challenges (or can recall), if you did this in the time of early wars where there were a finite umber of battles to be fought (Meridell vs. Darigan? Both wars?), you gave yourself an unfair advantage for personal gain (aside from the personal gain as it stands). On if other users have made use of such scripts, that's something to ask them, to which I'm sure the answer would be, "no sir."
And given the outcome of the Neggbreaker glitch, it's a given there is code to be taken advantage of. I don't need to repeat my feelings on that matter (ever am I redundant), so...