April, I love your intuitive spin on Angie's categories.
Here's a slight adaptation, riffing off yours:
1. Agree absolutely that if you need it, find it boring to shop for, but really can't get dressed without it, it's a basic. (However, we must make allowances for the fact that some women actually like pretty lingerie and enjoy shopping for same. Their underwear remains a basic...however pretty and expensive it is.)
2. Here, going with your description, I worry that people who struggle with fit issues might not see themselves. A woman who finds jeans, for example, difficult to fit, yet wears them four times a week. She might even resent spending money on them! Yet they are essential to her life and her style. Typically people in this situation will search for a replacement article of clothing that fits them better and works as well for their lives. So a pretty pear who struggles with denim fit might switch to casual skirts. But sometimes that's just not possible. The item remains essential.
3. A statement item might actually fill a need. For instance, some of my jackets are what passes for statement items (for boring me). I NEED those layering pieces in the cooler months where I live. Yeah, I could wear a woollen sack instead, but since I have to layer with something, it might as well express what I want (if I can find that).
Otherwise, I totally agree with what you say. Those items that call out to us in mysterious ways are usually statements....either that or....
4. They are essentials that have the potential to become SIGNATURE items. We've all agreed that a white button down is an Angie "signature" item. A jacket, in addition to being a F/W essential and sometimes a statement to me, is also something of a signature. I rarely feel dressed without one.
I think people can also have signature silhouettes (fit and flare -- oops, hope I am imagining that correctly! or long over lean) and signature colours (I associate Angie and Rae with sour brights and Deb with black and white and ink blue and red.)