Yes do so, they are cheap and use a USB 2.0 hub with its own external power-supply as that will secure that the dongle gets good power too. See example this → https://www.amazon.com/AmazonBasics-Port-USB-Power-Adapter/dp/B00DQFGJR4
Yes those are very good values, but I would not bother looking LQI or RSSI as they usually do not help troubleshoot interference. Instead just add many more Zigbee Router devices to each room in your home, however, if you want to go down the rabbit hole then you can start by reading this → https://www.home-assistant.io/integrations/zha#how-to-interpret-rssi-and-lqi-values
For the best you can get recommend to make yourself some semi-DIY Zigbee Router devices by buying and flashing the correct Zigbee Router firmware to good Zigbee Coordinator USB dongles and then using them as stand-alone Zigbee Signal Repeater devices in USB-chargers for power, like, for example, either the Sonoff ZBDongle-E (EFR32MG21 based) or the Sonoff ZBDongle-P (CC2652P) work great as dedicated stand-alone Zigbee Signal Repeaters when using Zigbee Router firmware.