The galactic center itself does not have a specific orbital speed as each object that comprises that area of space moves at a unique speed. The easiest answer would include the spin rate of the central black hole, Sagittarius A*, as well as the orbital periods of the closest surrounding stars, the Sagittarius A* cluster.

Per the two linked pages the black hole has an estimated spin rate of 0.1% the speed of light at the event horizon while the stars have orbital velocities between 0.15% and 8% the speed of light.

No doubt there, just look at what happened during the Carrington event. That flare was estimated at X40 and set telegraph lines on fire. If we got hit with one of similar strength today it would be devastating.

A major factor in the strength of a geomagnetic storm is the strength of the Earth's magnetic field. It's been dropping since we first started measuring it and has fallen by at least 20%. As it continues to drop weaker CMEs will cause stronger storms and strong CMEs that the field would usually just shrug off now have a larger chance to cause damage to our electrical infrastructure.

I do wish they would stick with one descriptor here. "A massive solar flare" and "The huge solar flare", please just pick one.😅

That said this was neither "massive" nor "huge". X2.2 is just the start of the X scale and there is evidence for flares in the X45 range and it's thought the sun can produce flares up to and over X100. Now those flares are "massive" and "huge" and can even be called unbelievable.