Does this iMac include a built-in camera and touchscreen support?

Yes, it includes a FaceTime HD 1080p camera. It does not have a touchscreen.

What are the key performance and display specifications of this iMac?

This Apple 24-inch iMac is powered by an M3 chip with an 8-core CPU, 10-core GPU, and 16-core Neural Engine. It has 8GB of unified RAM, a 256GB SSD, and a 24-inch Retina display with 4480 x 2520 resolution. The display also supports P3 color gamut and True Tone technology.