Some new information:
Packet capture with Ruckus proved issue out to my firewall (acting as the default gateway for my wireless subnet). After lots of troubleshooting, we now see this to be related to an arp issue that is only experienced by wireless clients. It appears that the Ruckus equipment will RANDOMLY interfere with arp request/reply between the client and default gateway, which causes a delay of between ~8-50 seconds of loss of [default gateway]->[client] traffic. Once an arp entry is put into the default gateway's arp table, traffic is immediately resumed. I emphasize randomly, because sometimes the arp resolution is done appropriately and no issues are seen.
If you are also experienced by this issue, then you can relieve the problem by increasing the arp entry expiration on your router. I set mine to 24 hours. Of course this is a workaround and not a fix...
The challenge now is for me to continue troubleshooting with Juniper support in order to procure evidence showing this is a problem with Ruckus' equipment.