Troubleshooting

Pinch to zoom doesn't work on Mac
Repeating keystrokes 

Make sure you have "Use scroll gesture with modifier keys to zoom" enabled in the system preferences, and you have enabled "Pinch to zoom" in the iOS app input settings.

If you experiencing repeating keyboard strokes, the problem might be with the latency of the network. In this case you might want to consider increasing the delay before keystrokes are repeated in the system Preferences.