Ctl Z does nothing (neither does command Z or Option/alt Z). In my prefs I have it set to undo up to 64 steps. I have restarted Blender, nothing. Neither the shortcut or the menu Undo command works. Google doesn't turn up anything.
open
Undo last step
They are called accelerators. They are shortcut keystrokes that bypass the command menu system and call the associated command directly.
ctrl an plus zoom the screen in an ctrl minus dezooms it
ctrl shift - reverses the effect of ctrl shift =
ctrl plus r reloads a webpage.
Ctrl plus Q, often written as Ctrl-Q or ^Q, is a key combination used to send a command to an application. It is accomplished by pressing the key labelled CTRL (labeling will vary with non-English keyboards) and holding it pressed while typing the letter Q, then releasing both keys.Keyboard shortcuts (often implement with key combinations) offer a fast alternative to using the mouse or more verbose commands to the experienced user.No standard meaning is assigned to Ctrl-Q; the interpretation is entirely in the responsibility of the application with which the command is used. Traditionally, Ctrl-Q would be used on text terminals to continue text flow after suspending it with Ctrl-S. Some terminal applications or console and command windows may still be inclined to interpret Ctrl-S and Ctrl-Q in this manner for traditional reasons.
Ctrl + 1
It makes what is on the screen bigger. Another way to do it is ctrl + plus or ctrl + scroll wheel up/down.
That's the first step to move the selected text or graphics. To go into a bit more detail, Ctrl-X is the "Cut" command. It erases the selected text, graphics, etc., from the document, and places it in a temporary storage. You can then recover this later - somewhere else in the document - with the "Paste" command (the shortcut is Ctrl-V).
It increases the magnification of the screen. CTRL plus _ does the reverse.
Ctrl plus J is used to justify text or a paragraph.