Tested things this morning. It "appears" that everything is now working. I got callerid on my display calling both GV numbers. I also was able to use the Call button. Either something got fixed by Google, or it fixed itself (reboot?).
If the Call button is going away, I guess I will have to read more on Hangouts. However, I have no intent of joining Google+ to do so, nor of having any ability to receive calls from people over the computer.
If I setup GV to make outbound calls on my OBi, then I lose one of the two SPs, which means I can't differentiate incoming calls on my two different GV numbers, i.e. they will ring the same. I like that distinction. Further, I don't want to have to setup things on the OBi portal, right now I control whether my firmware gets updated and OBi can't update it automatically. And, if OBi did anything drastic (closed, sold assets off, etc.) I would still have my CC service just fine.
I rarely make outbound calls when I'm not working at my PC, so having to use the GV call button is not a problem. We can dial 911 on the phone just fine.