I think your teacher is either "full of it" or "misinformed"
While it may be true that in English we usually enumerate parts of the body from the outside in, I'd suspect it has more to do with creating a physical starting point that is furthest from our eyes and looking for a way to create a list without forgetting something. I doubt this is limited to English, but is more of a "human" thing.
For random objects, I'd suspect people probably sort from easiest to recall to most difficult, or from most to least favorite, from biggest to smallest, by what sounds right or just randomly... or according to a set phrase, rhyme or song that's established culturally.
Lions and tigers and bears, oh my!
It's raining cats and dogs
strawberry rhubarb pie
They fight like cats and dogs
They're playing a game of cat and mouse
I'll have a ham and cheese sandwich
Would you like some cheese and crackers?
I'm having a wine and cheese party
I feel like a rum and coke
I'll take a Coke and Lime
In some of those examples, the more important element is stated first, but in many, the order has been established naturally, with less importance to order. Saying that, I'm sure there are certain patterns you could find based on how things sound together, or how many syllables there are... but the opposite is not wrong.
You certainly can follow hallucinating with a preposition, but I don't think any well describes the relationship between the hallucinations and the wallpaper in that story.
She was hallucinating a woman in the wallpaper.
She was having hallucinations, projected on to the wallpaper.
The wallpaper became the focus of her hallucinations.
I would all be happy with.
She saw hallucinations in the wallpaper.
I would also be happy with.
I'm inclined to the first, but that's partly because I think the fact that the hallucination was of a woman is itself significant in my reading of that story. You may disagree, or it may be irrelevant to your piece.
Best Answer
When used in this way, said is normally preceded by the. The definite article is, however, sometimes omitted, as in your examples. When a word is omitted, but can be retrieved from a previous part of the text, the feature is known as ‘ellipsis’. In the case of said, it probably occurs mostly in speech, rather than in formal prose, and may sometimes be intended to be amusing. My personal view is that said as used in this way, with or without the, is best avoided. It rarely adds anything useful and almost has the status of a cliché.