List of sketches disappears off the bottom of my screen
That issue has been fixed since the Arduino IDE 1.5.5 release, 4 years ago.

The version of the Arduino IDE you get from apt-get install arduino has not been able to be updated for years due to licensing issues. The versions available from various package managers may also be modified in ways that introduce new bugs. For this reason you should always install the official Arduino IDE version downloaded from:
https://www.arduino.cc/en/Main/Software