Mid February is getting towards the end of our rainy season. By that stage we will have had lots of rain and the river will have risen considerably, which means that the falls will be quite full.
However the main flow of water is that which arrives from the big catchment area in northern Zambia, this water does not arrive until around March April time.
So February is a good time, the Falls are full but not at there fullest. There will be lots of spray and as you go towards danger point in the center of the Falls, there could be an almost white out where the view is obliterated by spray. However you will still get clear views of the falls from the western end. It's a good time because you will get clear views from some vanatge points but you also get to experience the full might of the Falls.
I would definately view it from Zimbabwe as you will get clearer views from that side.
Most activities will be available except for the Devils swim and low water white water rafting, these will have closed by then due to the higher water. Microlight flights, heli flights, cruises, game drives etc will all be avialable at that time.
The only down side with February, is that the game viewing is not that good at that time of year and it is possible that rain can interfere with your activities, but then thats mother nature and no one can predict it and in February we can also have glorious days of sunshine.
I hope that answers your questions.