1

Iberia via Madrid. Check out skyscanner.net for any other flight connections.

Overland would be a nightmare.

2

It's possible to do it in a day if you leave early, but the all day bus-ferry-taxi-train trip would be exhaustive even without a 3-year old.
But if you're ready for it, give it a go.

3

I think the best option for you would be to take one of the high-speed trains from Sevilla to Madrid (book them online well in advance in order to get one of the web fares -up to 70% of discount) and to fly out of Madrid. You could take also a look at Iberia from Sevilla to Casablanca changing planes in Madrid and at TAP from Sevilla to Casablanca changing planes in Lisbon to see if it's cheaper. Another alternative would be to take a train or bus to Málaga and to fly from Málaga to Casablanca with Royal Air Maroc or Helitt.

Overland, you would have to take a bus from Sevilla to Algeciras, a ferry from Algeciras to Tangier MED, transfer overland from Tangier MED to downtown Tangier and a train from Tangier to Casablanca or Rabat. If you need details about the schedules of the overland route, ask again.

4

Thank you! Have you flown with Helitt or Royal Air Maroc before?