A:AnswerYes, you can. Please review the manual here: https://www.asus.com/us/Networking-IoT-Servers/Whole-Home-Mesh-WiFi-System/ZenWiFi-WiFi-Systems/ZenWiFi-AX-XT8/HelpDesk_Manual/
A:AnswerYes, this pair of units can cover up to 5500 square foot homes. https://www.asus.com/Networking-IoT-Servers/Whole-Home-Mesh-WiFi-System/ZenWiFi-WiFi-Systems/ASUS-ZenWiFi-AX-XT8-/
A:AnswerNo, one unit in this pair will act as the router, with the other unit being a satellite to extend your Wi-Fi mesh range. More information can be found here. https://www.asus.com/us/Networking-IoT-Servers/Whole-Home-Mesh-WiFi-System/ZenWiFi-WiFi-Systems/ZenWiFi-AX-XT8/
A:AnswerI imagine that the unit connected to the cable modem is fixed but you can move the other unit to a more centralized location or at least closer to your kids room
A:AnswerBoth will cost you a bit in a speed test. AiProtection not so much (~25 to 50 Mbps) but QoS can have a large impact (~100 to 200 Mbps) depending on how you have it set up
A:AnswerIt sounds like your Mac is defaulting to another network. Try going into Wi-Fi settings and ‘forget’ existing networks listed. Then when it asks, remember the new network.
A:AnswerThe vendor does state the AC5300 as compatible with AIMESH. Something to be aware is the AIMESH nodes with 3 wireless bands 2.4Ghz,5Ghz-1,5Ghz-2) will use the 5Ghz-2 band as backbone to main station unless the ethernet backbone is connected.