Unexpected behavior on some keys

[utc-zz]

When the cursor is placed within a comment (not at the front column), pressing the 'END'-key sets the cursor to the first column instead of jumping to the end. It works as expected if the cursor is at the front of the line.

Another key that behaves differently than in every other editor I know of is the 'ALT+Backspace' combination. Usually this is identical to 'CTRL+Z' (Undo), at least under Windows.

And another one: when pressing 'Shift+Pos1' I would expect the editor to mark everything from the current cursor-position till the beginning of the line and jump to the beginning. Currently this jumps to the first non-whitespace character of the line, which is also acceptable. BUT: if the cursor is already placed right before the first non-whitespace-character and there are whitespaces to the left, then nothing happens. One has to press the key combination again to mark the whitespaces at the left.