We used to live in Casablanca, Morocco for around 4 years a while back. Yes, mid-Feb is still the back end of the cool period but is close to Spring depending on altitude - so think positive and enjoy this lovely country!
9 days is brief for all that can be seen. The "Royal Triangle" that is all within reasonably easy reach is Marrakech, Meknes and Fez and those 3 would happily fill your days (and nights) with fascinating insights into Morocco. An optional stop on the coast at El Jadida could be added but the above "3" are absolute highlights!
Casablanca is just a commercial city so (with respect) please discount it. Rabat and Tangier are fine but not for a short stay. Equally, tripping over the mountains from Marrakech down towards the Sahara is probably not ideal for a short trip as there is quite a lot of road travelling time involved. However - if you really want to do this, I can produce some ideas for you.
I hope you enjoy your trip. It was one of our highlight stays!