First trip, first draft

All looks great to me as a first trip to Iberia - except I'd skip the Tangier side-trip. IMHO that day is better spent in Spain or Portugal.

The Iberian peninsula is large and diverse, and there's more to see and do that most people first think. With 4 weeks you can see a lot (not all) of it. So I'd skip the "day trip to Africa". Save Morocco for a separate trip when you can give it justice (it's absolutely a worthwhile destination - I've been 3 times), but the best parts are not found in the north coast ferry ports. Give Morocco a week or 10 days at a minimum, and with both Spain and Portugal, you have a full plate already.

You will find that renting a car in Spain and returning it in Portugal (or vice versa) comes with a surprisingly big one-way charge. Investigate that (and consider alternatives) before getting too settled on a one-way rental. Many people struggle with the logistics of this country pair. There are ways to get around this but they're not trivial.

Yes, I forgot to mention the car issue; we're fine renting in both countries as needed and appreciate advise on border crossing options.
I appreciate the insight on Morrocco.

Based upon your OP I suggest breaking the car rental into two smaller, county-specific rentals. Then, use trains to cover the longer distances. This will keep the long drives to a minimum. And, if you spend three nights each in Barcelona, Madrid, Granada, Sevilla, etc., you will probable not use the car for at least two of the days you are in each city.

Agree that traveling home from Lisbon is a the way to go to negate the need to backtrack to Madrid, etc.

Agree; Fly to Barcelona and sound minimum 4 nights there before tasking train to Madrid.

After Madrid, take train to Sevilla; stay there 4 (?) nights and only then,, rent the car at Santa Just a train station.

Skip Ronda..it's out of the way of you are headed for Tarifa and there are other "white towns" that are just as beautiful, with fewer tourists.

If you can skip Tangier, drive from Sevilla to explore the province of Cadiz province (Arcos de la Frontera; Sanlucar de Barrameda; Cadiz city; Vejer de la Frontera; beaches of the Costa de la Luz, etc) before heading to Portugal. (see about returning the car in Cadiz city and taking public transport into Portugal for the second car rental)

No need to go to Tarifa if you are not crossing the strait.

I’ll start by stating I almost always rent a car and plan trips so there is no more than 3 hours a day of driving with a couple stops en route to break up the driving time. We seldom visit the large cities any more since we’ve been to the ones we were interested in.

A rental car is very handy if you plan on visiting small towns, villages, and hamlets that are off the beaten path and not well served by public transportation. With the exception of the white hills towns, the places you mention are served by bus or train. There’s no need for a vehicle in Granada or Sevilla. Driving in large cities is a pain and parking will cost €20-€25 per day.

Once you decide where you’re renting the vehicle research to towns along the route you decide to take to find towns with sites of interest to you. There are plenty of towns and villages that see few tourists. Once a route is known, I can let you know places that we enjoyed visiting.

In Portugal, most of the main roads are toll roads. They can be bypassed by taking the rural roads, but it will take longer to get to your destination.

An alternative to returning the rental in Cádiz might be returning it in Huelva. It’s closer to the Portugal border and some of the major rental companies (Enterprise, Alamo, National, and Europcar) have locations there.

Fly to your furthest destination then work your way back home so yes, fly into Barcelona. From Barcelona, fly to Granada and when you’re ready to leave rent a car and drive to Ronda then to Arcos de la Frontera. Drop off your car in Sevilla and take a direct bus from Sevilla to Lagos, PT. You can take a direct bus from Lagos to Lisbon.