Which tool allows you to erase the color currently under the centerpoint of the cursor?

Keyboard shortcut quickly switches the foreground and background colors?

Which feature blurs edges by building a transition boundary between the selection and its surrounding pixels?

Pressing Cmd (Ctrl) + Z Toggles the last history state in Photoshop. What do you press to keep undoing?

How do you turn a standard layer into a background layer?

Shortcut for the eyedroper tools is

.... helps change the spacing between all letters in a word by the same amount.

Option in Stamp tool to clone all the layers simultaneously?

..... is a process in which Photoshop responds to your size-change

The Mode pop-up menu of Puppet warp tells Photoshop how stretchable you want the mesh to be.

What are the names of the tools marked in red in the image above?