NO.

There is more as 1 ferry comp on these lines-and some give discounts to ju/se-nior or even the odd passholders (that is, if the counter is even able to recognise it).

You-again-do not have to worry about REServ monthes ahead-that is (weeks then) more for people with cars-normal foot pax are not so normal anymore as you can fly for less as 20€ on nearly hourly flites with low-cost airls. so the very few remaining to still choose this option simply come to port (DO check very carefully where that is-it may be miles out of town without a proper bus=thats for the cars) and buy at counter-just like a ticket for the GO-train.

Note: you may see very low prices advertised-but these are ONLY for locals with proper ID from the place they live in. There are currently also quite high FUEL surcharges.

You will not have to use a travel day on the ferry as you won't travel for free on the ferry, you only get a discount on the ferry price. Travel days are only used for days when you travel for free. To get the discount the ferry trip must be made within the validity of the pass. You shouldn't enter the ferry as a journey in your pass.