For Black Ops, make sure your dump is good. Right-click a game Black Ops in Dolphin's game list, go to Properties, then go to the Filesystem tab. You should be a couple of Partitions. Right-click these, then choose Check Partition Integrity. If you get any errors, redump/rerip Black Ops and try again.
If you still get these error, go to Options -> Configure -> Interface tab, and uncheck Use Panic Handlers. This should stop the pop-up from happening, though you may still experience issues while playing (since this just gets rid of the error messages, not the errors themselves).
For controller configuration, I can't really say how to best setup the Wiimote + Nunchuck. For this game, actually, I'd recommend setting up the Classic Controller in Dolphin.
If you still get these error, go to Options -> Configure -> Interface tab, and uncheck Use Panic Handlers. This should stop the pop-up from happening, though you may still experience issues while playing (since this just gets rid of the error messages, not the errors themselves).
For controller configuration, I can't really say how to best setup the Wiimote + Nunchuck. For this game, actually, I'd recommend setting up the Classic Controller in Dolphin.