Beginner question about OP AMP as "DC differential amplifier". Does switching inputs between + and - make any difference?
is that what's called a &quot;DC differential amplifier&quot;?

No.

Would it make any difference at all if I switched the inputs around

Yes. The circuit would no longer work as designed.

my assumption is that switching inputs around as I described should make no difference at all. Could that be right?

No.

Could that op amp circuit (with mosfet removed) be used to &quot;convert&quot; a voltage controlled boost IC into a current controlled circuit by replacing the &quot;standard&quot; boost IC feedback divider with the output from the op amp?

I don't understand. Could you provide a schematic?