Eric

Impressive

The center of that arch bears no load, and the doubled 2X4's (if not 2X6's) on either side can handle a lot more; feel free to remove te 2X4 studs. The only thing they support is the cap and trim making the window in the arch.

Yea, that was my thinking. Leave the two columns on either side of the arch. continuing the opening down should be safe.

Also, from the looks of it, the current "shelf" is 2X4s laying flat rather than on end. "On end" provides much more support. All leads me to conclude the wall and arched window is for looks and not structural at all. Good for you as far as flexibilty.

It would probably take me 45 minutes from cut to clean.

Intriguing.

Might I bring up; instead of tip-toeing around with that short wall, just cut it right out and put in exactly what you need? Go straight down from the existing opening. You know where the one wire is.