Die2Nite is a game of teamwork so you're not useless ever, even if you don't have hero actions. That said, the scout abilities are definitely more valuable during the early game.
You benefit from being able to travel through zones unseen (by zombies) and you're able to see zombie counts in adjacent zones. These things are critical for finding buildings and leading other members around before the watchtower is upgraded to level 2 or 3 (it'll detect zombie counts on the map after that).
In my experience, a good town requires a certain number of players who do not go out into the world and just spend points on construction after a certain point. You may be a perfect candidate if you've already make your early game impact as a scout.
If you are still insistent on leaving the town, you can still move unrestricted on the map. Combine that with a powerful weapon and you can make a nice dent in an area of heavy zombie infestation. Considering that zombie counts are highly dependent on the zombies in the area and zombies killed, that kind of thing makes a difference in how the zombie population grows.
As for traveling, you're restricted by AP just like everyone else. There's no special trick for traveling long distances if you're not a hero (and if you are, use Hero Return) other than to make sure you don't waste your AP when you're in the world.