Tangiers is safe to walk around in daytime and the souks are very busy and bustling. They are a hive of activity and each yard you step you will be mithered to buy their wares. Its an experience but be form and say no then walk on. Pasy close attendtion to your valuables like anywhere. As yuou will get off the ship , unofficial guides will appear all around you to show u around, Ploitemly say no and walk on, tHey will probably walk along side you for a while.
There are lots of leather products etc from the souks. Good value but barter hard. Whatever their price reduce it right down . If for instance they said 50 pounds id offer a fiver and worjk up . lol.
Its a very dirty country in and my first thoughts at one time was like beirut but its a ok and worth visiting. The madinas are really nice.
Both are safe to walk around, Casablanca especially so, BUT you will be pestered.Be firm, be polite.If you are intersested in anything, then bargain, Do not say "Maybe"- that's a yes
A cab makes life easier, but bargain hard and agree what you want, where you want to go, how much you will pay There are a lot of "Rick's cafes"- all overcharging!
Morocco is one of the safest arab countries to visit and tourism is very important to them so you should be absolutely fine. But like anywhere that's foreign to you - stick to the tourist areas, try not to go off the beaten track and keep an eye on your valuables - this isn't a Morocco thing - I'd say the same if you were going to the London or Barcelona.