Advice... go out and get yourself one of those
pool blow up air matresses with the pillow. The cheap ones. The athletes village hase a couple big tents, and the only place to sit is on the ground. So the blow up matress works great, and you just leave it there when you hike to the start.
Also.... do the Freedoms run the day before the marathon. It's free and it's a shor 2.5 mile jog/walk thru town.
Lastly: I opted to go to dinner at one of little Italian resaurants around Paul Revere's
house instead of the pasta dinner. I did that the first year and I was in a line 1/4 mile long. Have fun... Boston is a cool city.... but real pricy !!!