3. There is no reason to short rest. Or, rather, there is no reward for not long resting and playing through more encounters in a day. Since the game still has attrition elements like long rests not recovering all hit dice, the cost of a short rest is often not a lot lower than the cost of a long rest. Since a long rest does everything a short rest does and more, the only reason you ever really need to short rest is when you're under time pressure, which simply isn't appropriate for every adventuring day in every campaign. Worse, if your campaign has real time pressure, then you often run into situations where the players can't short rest, either!
I believe you are only allowed 1 long rest per 24 hours, so you would have to essentially skip an entire day to trade a short rest for a long rest. In most campaigns there are going to be ramifications to that.
You might expect to hide out in the pirates bedroom for an hour, but you are not going to hide out there for 19 hours. Lemunds hut is not really viable in the middle of a enemy camp. You can leave and come back but that presents all sorts of problems - another group goes in and steals your loot, the baddies find out someone came in through a secret entrance and now guard it, the kidnappers realize they have been found and split town with the princess.