Damn thats a fine looking ship...
The ship model is offered by Thargoid for this project (here
is the original ship) what I shrinked down to 30% to make a little brother which can fit into normal docks. Fortunately the carried ships nicely fill the side decks so I do not need to made a new model. I am a programmer so I love script making but I can not make nice models yet.
the carrier can hold 50t and each cobra mkI holds 10t ,you have 5 docked so thats a total capacity of 100t? or is it that the cargo capacity IS the 5 cobras?
The total cargo capacity is 100t with 5 Cobra Mark I on board, but you will not see this in one piece. You will be able to switch between your ships when you are in a dock but you will see one cargo bay at a time. If your goal is a really big trader ship then gather enough money to buy two Anacondas into your carrier.
I love it, but how is it meant to be used by players? Are there squadmate/wingman commands I'm not aware of? Is this a 1.8 thing?
You bought all ships so should follow your commands. For example you can choose your ship before combat and others will serve you as escorts, including the Carrier. Many commands like "attack my target" are implementable in scripts so I think this will be well playable in Oolite 1.77 also.