Do you ever use the balance on your pre amp?

Ah, the tribulations of the Rich and Famous :>)
My wife and I had a standing joke about how every system we set up in our earlier years needed a twirl of the balance control to adjust for what we blamed on living at the wrong location relative to the position of the moon and planets.
Then I decided the quality control guy at each factory took his lunch break while our particular units came down the line.
You're right about a particular rightness when the listener is positioned where the recording engineer centered the image.
Next, I can predict you'll become aware of the off center (but, real) positioning of certain musicians and vocalists, who also occasionally dare to turn their heads, further complicating things.
The ultimate solution to all of this is for minimalist high end manufacturers to re-introduce the long gone balance control, this time as a remote control feature.
Meanwhile, I have pressed back into service my KLH 21 table radio whose monophonic imaging, and limited bandwidth, hide all the rough edges in any recordings.
"We don't need no stinkin' balance control."

Vote me in the Balance control camp, I have the same issue with vocals and stage right...so the slight scew is a nice option, wish I didnt need it but glad it is there.

I guess I must be lucky, as I don't have a balance control, nor do I feel the need to use one. On almost all of my recordings, the imaging is solidly centered.

(Once in a great while I do get the odd record where the image seems really off, but I either just live with it, or move on to the next record. Oh well, no big deal to me.)

Sure, why not?

On the other hand, you could rearrange your room and put the speakers equidistant across a common corner -- or just simply position the quieter speaker an inch or so closer to the listening position. Playing with toe-in, and putting acoustic damping material on the closer side wall could help quite a bit too.

Absolutely. I find that maybe 10-20% of the recordings I listen to have images slightly off center. A touch of the balance knob can center the image easily. I consider a balance control mandatory, just like a polarity invert switch, and to a lesser extent, a remote control.