Thank you guys! I was able to configure outbound calls. While doing it learned that apparently my KX-TGP550T04 only supports 3 calls at the same time, which essentially means if I am to use this phone, I really only need 1 GV account, as the other ones will never get used, and then I can actually downgrade to Obi100 from Obi202. Nonetheless it was an interesting exercise and introduction to Obi setup for me.
Now I'm trying to configure Google Voice to ring on my Panasonic phone, which seems to be a challenge as well. I configured SP1 ->X_InboundCallRoute as {SP4(123456789@local_client),ph,ph2}, but my VoIP phone on SP4 doesn't ring. Analog phones ring just fine.