1. First, command+ plus sign or minus sign can enlarge or reduce the time axis, as shown in the figure below.

2. Then shift+Z can reduce a long time axis to the visible area, as shown in the figure below.

3. Then control+D can change the duration of the selected segment, as shown in the figure below.

4. Then shift+c can quickly add the ken burns effect, as shown in the figure below.

5. Finally, command+T can quickly add a default transition, as shown in the figure below.