inverted word order

[chum]

1. Boy! Was I angry. I don't know the rules when it comes to inverted word order. I think, a question mark is appropriate after "Was I angry"...Is it possible that it's also a good sentence that should end in period?

[Mister Micawber]

.
The inversion suggests emphasis, and I would end with an exclamation point:

Boy, was I angry!

A question it is not.
.

[dihen]

A question it is not.

Why not "Not a question it is."? And wouldn't it sounds strange like this?
`
A question, (one-second pause) it is not.
`
This is much worse:
`
A question. It is not.
(Wouldn't it sound like "What?, you're saying that it's a question and then saying that it's not a question?"?)