Hello,
The logs do indicate frequent disconnects. What could be suggested, is to try using a different WiFi channel, specifically channels 1 and 6, and switch between 20 and 40MHz channel widths. However, this applies only if you live in an environment, where there is a possibility of more nearby access points surrounding you, as disconnects may be due to congested spectrum and interference from other APs.
Other than that, there is a single instance, where wireless interface simply goes down, which appears to be related to faulty drivers or hardware, and in this case I would suggest to simply return or replace the device.
Best regards,