I've not read all the posts and don't have time to so I'm just gonna add this ... I think it's really important that if you're going to do something like this, you should read into the dangers of it and the damage it can do.
Come on, if you have time to post all that, surely you have time to read two pages of posts (a bit ironic, considering your exhortation for people to "inform themselves").
If you had, you'd realize BabyCleo is not doing CIO at all, in fact, I think she is barely even doing CC. It sounds to me (someone who has never done crying-based sleep training) like she has a baby who just needs to blow off a (very) little steam before sleep.
I think there are generally two types of babies. Some will grizzle a little and then quickly drop off to sleep. Others will cry for long periods of time before eventually giving up. Some of the second type will escalate to screaming and throwing up.
The first type of baby can probably be "sleep-trained" quite easily and without harm, because they are well suited to it. The second type is, I think, much harder to sleep train and will probably suffer harm from it (it probably also won't stick, and you will have to retrain multiple times). The screamers probably won't be able to be sleep-trained at all.
Much as I'm sure you're trying to be helpful, I think every baby is different. My babies are both of the type who would not suit sleep training. But I have come to realize that some babies are quite different to mine. Applying a one-size-fits-all philosophy to sleep training and telling anyone who tries it in any form that they are damaging their child is, to say the least, not helpful.