@Xcessiv 

Even if node three was connected to node two, node two would use the wired connection for quick communication to one so I don't see one or two being affected.

@Xcessiv 

The WiFi penalty will be between Node #2, and Node #3 which is 100% wireless. 

Worst case, you are playing an Interactive Game on a computer connected to Node #3 (either WiFI or Ethernet) the data will flow bidirectionally through Node#2. No if you have a high data consumption device connected to Node #2 via Ethernet, then they will see no noticable spee decrease, but if they are connected via WiFi to Node two, then that device may see some degree of speed inmpact and or the gaming device, connected to Mode #3 may be impacted by the computer demands from the connected device on Node#2.  

It all depends oh how much data is being demanded and or pushed by the connected devices in realtime.