As you have an iPad Pro, I presume that you have updated to iPadOS 16.2 - this being the most recent version of iPadOS.
If you have enabled Stage Manager, this being a new feature of iPadOS16, the finger corner-swipe Screenshot and QuickNote gestures are not available while Stage Manager is enabled. The corner-swipe gestures remain accessible using an Apple Pencil.
Otherwise, Screenshots can still be triggered using the physical buttons:
Take a screenshot on your iPad - Apple Support
As for the mini “floating” keyboard, you can easily return to the normal on-screen keyboard presentation using the two-finger “zoom” gesture (i.e., the reverse of the two-finger “pinch”).
If the Split Keyboard is restored instead of the full on-screen keyboard, you can either use two fingers (one on each of the two half-keyboards) and swipe the two halves together - or touch-and-hold the “keyboard” key, then slide your finger to the Merge & Dock option and release.
Use the floating keyboard on your iPad – Apple Support
Split and move the keyboard on your iPad – Apple Support
Finally, the easiest method to shut-down your iPad is to do so from iPad settings:
Settings > General > Shut Down