Along the same lines, if a query only returns 3 or 4 rows, they should auto-fit to the data, not end up so wide they take up the entire window width.

Default should be 'auto-fit' to results and let users drag a handle to change width as desired. Select all columns button (or upper left corner next to first column name) should be available like in Excel or SSMS and then allow for changing width of all columns at once.