Backspacing and Offset - the never ending headache of wheel shopping

Not QUITE right.
A ten inch aluminum wheel is really eleven inches wide, from edge to edge.
So a ten inch aluminum wheel with 5.5 backspace is zero offset.
I'm old. I don't care for offset, because it has to be calculated, and you have to know the wheel width. Backspace can be measured, even with a tire on the rim, and not knowing the width!
Tell me wheel width and bs, I'll have a good idea if it'll fit. Offset tells me nothing, cause I don't bother trying to figure out mm or + or -.