Thanks a lot Solivagant for this detailed answer! It will unquestionably be of great help. The description from the ecotourism website appears especially good. I will without a doubt try to contact those guides when I will be actively planning this trip. I will let you what the outcome of it will be.

wojtek
With all Moroccon sites you probably mean 1 week for the ones I listed? As I think 1 week is not enough for ALL.

anyhow. My Moroccon trip is off the table for now as flights from Netherlands are banned again.
I now booked a 5 day trip to Trinidad & Tobago as KLM has flights direct now and I had plenty of miles to book it. allthough no WHS, it's a new country for me. Will visit the 3 TWHS though.

Now aiming at either February or April for Morocco.

I think Tetouan and Ksar are difficult in a week (Sat to Sat), even more so if you add the Aire (T). The central ones are connected by high speed rail, so should work. The coastal ones are a bit of a detour, but should fit.

To fully cover, I think you will need two weeks.

No, I mean all. My itinerary was as follows:
Day 0 - late arrival in Agadir, overnight in Taghazout
Day 1 - Essaouira and Mazagan, overnight in Rabat
Day 2 - Rabat, evening and overnight in Tetouan
Day 3 - Tetouan in the morning, Chefchaouen, Volubilis, evening and overnight in Fez
Day 4 - morning in Fez, then Meknes, long drive on excellent highway to Marrakesh
Day 5 - Marrakesh, overnight there
Day 6 - Drive to Ait Bin Khaddou, overnight nearby
Day 7 - Drive to Agadir, late departure

Of course it is not doable if you use public transport or want to accomodate some distant TWHS, but for the current WHS one week may be enough.

No public transport for me normally. Always rentals. If booked the right way a rental can be dirt cheap.

I will check your itinerary. I think I'll keep it for the northern part in a week and later fly to Marrakesh and do those places. (Marrakesh itself I have been already). But maybe let's see what is possible.
Tnx for your suggestion

We all have different travel styles, so if this works it works.

For me that itinerary would undersell Fez and Marrakesh. It is certainly enough time to see the main sites, but for me these cities very much benefit from more time.

I definitely agree with this. Moroccan cities--while their "facades" as cityscapes appear similar--deserve much more time. But if the goal of the trip really is to tick off the list in the fastest way, then I think one week is doable with a rental car, as previously stated,

I have only been to Tétouan on a daytrip but I can't see the medina's being worth exploring on your own just "looking around" - you'll need a guide or good info to get around these places, see the niches and get the vibe - rather than just sit in a cafe at a crossing and tick it off. The problem with the medina's is a bit like traveling in SE Asia or some parts of Europe: you'll "temple", "church" out and they start to feel the same. My guide in Tétouan was saying if I'm been to Marakesh I won't enjoy Tétouan. Anyway, my point is that I'd recommend to look into a tour of these, paid or free whatever is available.