The player that you have screenshotted will be classified as abusing bugs and glitches. Please report him at https://pika-network.net/report.
In the meantime, you can report this bug at https://pika-network.net/bug-report/.
Sorry, but there is not a direct method to download the official PikaNetwork maps. Some of the maps that were added to Pika has its own thread and then approved by the developers, so maybe you can search them up and they provided direct download links.