Yes, during the purchase process, in addition to the purchaser's details, you must also indicate the names of the people who will be attending the Festival.
To buy a ticket for the Rototom Sunsplash you have to access the tickets page of the festival website and click on the type of ticket you want to buy (festival only, festival+camping,...). A window will open with the sales widget. Fill in the ...
No, it is not possible: the days of Festival and Camping must be the same, so for 6 days of festival you should buy the ticket "Festival 6 days" and "6 days of Camping".