Hey Peter,
I'm glad you went for it - the smaller fish clearly has the look of a juvenile and is certainly the right size, congrats on your new pair
Once settled in the tank you should expect chasing, but no biting and there should be no "corner cowering" by the smaller fish. It will "run" from the male for a few seconds then casually go about its business -
Tank temperature affects spawning for the genus in general - so if they aren't eventually, and you want them to, try turning up the temp. a notch (~81-83 F)