Hi Blanche,
I´m glad to get a message from the founder of WorldCycle Videos on Vimeo. Your video "Tamazight" and Jan´s site marokko-per-rad.de were the main inspirations for our first Morocco bike tour in February 2012.

This year we want to continue our 2014´s tour, which found an unplanned end at Tazenakht, where all river crossings were blocked after days of heavy rainfalls. Our destination in 2017 will be Sidi Ifni, the southernmost place of our tour in 2012. If everything works, we will arrive at Sidi Ifni on 08/03/2017.
https://www.bikemap.net/en/route/3881673-ma17-tazenakht-sidi-ifni/

Yes, I think it´s possible to buy tickets and make seat reservations for CTM busses
You can pay with international credit cards (My Visa Card didn´t work, because it´s not registered for "Verified by Visa"). But I found no options to make reservations for baggage oder oversized baggage.
http://www.ctm.ma/

Is the price of 50 - 60 EUR for a taxi from Sidi Ifni to Marrakech? This would be really cheap! We fly from München (180 km from home) and have to pay about 90 - 100 EUR oneway for a rental car without driver. We will ask the owner of the Riad in Marrekech to make a bus or taxi reservation when we arrive.

Thank you for your informations. I hope to see new cycling videos by Blanche on Vimeo soon. I´m a photo and video amateur, but I will give my best. Some weeks after our return from Morocco you will have to decide, if our newest video is worth being added to your channel WorldCycle Videos.

Thomas