The size of the room doesn't matter because it is only a cool breeze directed at you, it will not cool any size room.
It doesn't get cold, it is a cool breeze. As to a fan, they are generally much larger. The breeze is not the hot air just passing by you, but is cooled by the evaporating water in the unit, better than a fan in that regard, a personal handheld fan. In the manual there is a chart that shows the temperature drop in the breeze depending on outside temperature and humidity.
No, it is just a narrow breeze cooled by evaporating water. It would be more equivalent in capacity to a personal handheld fan, but better.
Per manual 3 to 8 hours. My experience which depends on outside temperature and humidity is closer to around 4 hours, but I ran it only on hot Summer days.
Empty, no water, 14 ounces.
No, not that I've experienced yet, but I've only owned it two days. Further testing is required.
No reason why not, it has a USB plug, but it's filled with water to work which could get sloshy on turns.
I just received mine and see there is a filter but cannot find a reference yet on how often to replace or clean. It replacement filters are needed, I'm not sure where to buy them.
I would think it would work where ever you used it. The machine is not "humidity-regulated" where it shuts off when too much or too little humidity has been registered.