When you press a TAB in the last row, of the rightmost column of the table, a new row is automatically added.
Select the Entire Row, by clicking on the first column of the required row and press delete.
To sort a column of values, simply double click on the column header.
No, you cannot do this. The sizes have been so adjusted that you do not need to scroll horizontally when any row is displayed. However you ZOOM by pressing the "Ctrl key" while moving the mouse wheel.
Use the familiar windows copy and paste shortcuts (Ctrl-C and Ctrl-V). You can even copy entire columns.
Disabled cells of the table where user input is not allowed are grayed.