I actually find the "?" enjoyable in that they feed my desire to just go out and wander and explore the world. I find it fun to just set out into unexplored territory and see what's there. That's one of the big pulls of an open-world RPG for me. I spent the last couple days just running around doing 80% of the "?" on the west side of Velen. I like seeing parts of the world I have no idea about, seeing how far I can go or if I can survive. Eventually, once I'd circled from a point north to a point south, I got tired of it, and I headed back to the main quest, but it was a good break. Otherwise, the game feels too linear to me, and I don't really get a sense of the open world.
You can't use the Option menu within your game. You have to quit out of your game and go to the Main Menu. Then, I believe there is an option for Downloadable Content, and it'll be there. At least that's the way it works on PS4.