We recently spent a week sailing around these parts. All pretty straightforward as long as you do the usuals - watch the tide/wrecks outside Gib harbour etc. Oil tanker,pilot and Moroccan fast ferry dodging was fun in our saily boat, but shouldn't cause you hassles. Saw lots of dolphins and turtles throughout our stay.
We worked our way up along the Spanish coast (- which felt more like the South Coast of England than Spain) and then crossed the Straits to Morocco which we found far more authentic - we stayed at Smir (which I think is technically Spainsh territory) and also at Ceuta. We found a fantastic restaurant in the grounds of the ?castle in the old town in Ceuta.
The Morocccans didn't seem to have tricky immigration procedures - we didn't need visas or anything else - though try not to rock up at prayer time as everything seems to shut down then. Lots of form filling and passport stamping both on the way in & out, but again fairly uncomplicated. They're still a bit jumpy about swine 'flu and asked all our crew to parade through the marina office to be "inspected" by a doctor. This involved him literally looking at us for 5 minutes. We found that a smattering of French made us quite popular with the officials and seemed to help us on our way.
Watch out for requests to take "packages" back to England! Also, importing and exporting Dirrams (Moroccan currency) is reported to be illegal. We had no problems paying in euros there. We saw no leisure ribs there at all. The local police forces had a few ribs and we saw a suspicious couple of ribs with 6 x 250hp Suzukis on the back
, so I'd expect a bit of interest from the feds if you're planning on making the trip in anything decent.
Hope that helps!