Hello. You can select multiple controls by (1) holding Ctrl while you click each of them; (2) dragging a selection rectangle around them; or (3) by clicking the first control, holding shift and clicking the last control in the block. After you have all controls you want selected, change the length and height in the editor by entering the value you want and hitting ENTER. You can also resize the controls with your mouse, and the change will be done to all of them at once.
To align them, select all of them as indicated above and go to the Align menu and choose the alignment option you wish.
To undo, go to Edit->Undo in the editor, or hit Ctrl+Z.