I know what you mean. You don't want to take your hands off the keyboard while you are editing a cell. Suppose you have a formula =SUM(B1:B3) and you just want to edit one or both of the references. You can press Option-Enter to start editing the cell (or Alt-Enter in PC speak). But then to replace the cell reference, in Excel you would press F2 and it releases the keyboard into a 'cell selection mode' which only finishes when you press Enter. In Numbers, you have to pick up the mouse and select the cell or cells, or you have to type them in literally 'B2:B5' for example. I miss this feature a lot, too.