Was recently asked by a user about why some things are written as they are, such as the whole RGBA32 vs RGB24 thing. One predominant example is post #2778961, where the apparent addition of the alpha channel led to an almost 1MB increase in filesize. I suppose that discussion would then become "is the alpha channel meaningful and worth uploading, even if it doesn't store any information, as long as its intended by the artist?"
Aside from that, I'd also like to mention this: Keep in mind that for most of these "tips" that this only applies to images that are provided from legitimate sources, by either an artist or official publisher. Uploading modifications, even helpful ones, that are third-party edits *should* be avoided, unless you're uploading scans... then in which case it might just be better to request an image replacement in the image replacement thread.
By the way, I did mention you could Dmail me for any specific questions, but if you feel your question is rather broad or would help to extrapolate a discussion, you're also welcome to bump it here and I'll try my best to help.
And err, don't be afraid. I know it sounds all technical and stuff but my goal is to help this become easier to understand, not scare off other users out of uploading duplicates or what not because it can be somewhat of a difficult topic at first.