Loads of info here from the 2013 Motorhomefun trip
http://www.motorhomefun.co.uk/rallies-meets/59283-morocco-2013-a.html
Great country, we had a blast and can't wait to go back (15th Jan)
One of our group did have a dog and had no problems in or out. Not being a dog owner however I have no idea how he did it or what was required. There have been subsequent threads on Fun detailing the requirements.
Plenty of big rigs in Morocco such as Concordes but not a lot of RVs. generally you shouldn't find a problem with size. The main problem with the roads is potholes, general chaos in towns, and donkeys everywhere.
Re breakdown insurance - it's not normally available from uk providers. ADAC in Germany provide cover at very reasonable rates but have apparently stopped accepting UK vehicles possibly due to some dispute with the AA which is their UK partner.
However Moroccan mechanics are the tops. It is very difficult to get parts because they all have to be imported (and customs is difficult and expensive) so the Moroccans are excellent at REPAIRING things rather than just replacing them.
I speak from personal experience as we broke down and had to wait three weeks for parts from Germany (delay mostly due to Customs) but the labour cost was really, really low. And those boys know what they are doing. This was before we had signed up with ADAC!
We also had some bodywork repaired at a cost of euros 150 that we were quoted £1500 parts and £500 labour in the UK. Cracking job too!
Somebody on Fun who has been to Morocco many times says that if a Moroccan mechanic can't repair it, it's time for the scrap yard!
We also had solar panels fitted for euros 130 each yes that was FITTED not just supplied. And again they did a good job, much neater than the UK supplier had done on the two existing panels as far as the cabling on the roof was concerned.
I think that if you have toured Spain then you will find it no more difficult in Morocco
Oh, and the average campsite is about £5 per night INCLUDING electric.
And diesel is about 75p a litre.