I looked at the AR-One (same model as yours) at a recent RV show, because it was small and light, but decided it is something I would not buy. It is built to be light and inexpensive, thinner walls than typical for stick-built TTs, equipment borrowed from pop-up campers, under-size heating and cooling. I don't think it is adequate for my climate, probably not for anywhere in The South during summer.
I suspect that a lot of people buying these new small lightweights (Starcraft is not the only company building them) expecting something the same as conventional RVs, just magically lighter weight, will be disappointed. This will be particularly the case for first time buyers, no RV experience, no idea of what they are looking at or maybe not even what to look for.
The fridge is what it is, a 3 cu ft box with a small cooling unit, concentrated around the freezer space inside. If the freezer gets cold, the thing is working. But it can take a day or two of running, before this type of fridge is cool enough to keep food cold. I start my much more capable 6 cu ft RV fridge at least 48 hours before I am going to put anything in it.
If the fridge will not keep cold food cold, it is not working well enough, and that can be partly a climate issue: how hot outside, how much sunlight heating up the wall behind the fridge. If the fridge will not cool down warm food, that is something it is not really designed to do. Actually, the fridge installed in the AR-One was the first thing that turned me off about the RV. I know by looking at the size and model that it will not be adequate to my needs. I carry lots of frozen foods, like to make ice, and like my ice cream frozen hard. There is not a 2 to 3 cu ft RV fridge designed to do that. Those in the 4 cu ft range are a little better, if well located in a space that doesn't get too warm.
If you are always going to be hooked up to electricity, the dorm fridge is not a bad solution. It might be putting extra heat inside the RV, which might challenge the small air conditioner more. But given the choice in a RV between an ice box and a 2-3 cu ft RV fridge, I would probably choose the ice box.
A RV water heater mounts entirely inside, and substantially heats up the space that encloses it. They are not usually mounted under a bed, nor close to the refrigerator, that's just bad design. (Nor should the furnace be close to the refrigerator).
The water heater should, however, not be heating the enclosing space enough to produce combustion gases, which will be what trigger the smoke detector. There are a few possibilities. The water heater might be installed too close to the enclosing structure; there are clearance specifications for all of these appliances, and getting too close to flammable structure would be an engineering mistake. The installation could be not sealed properly, and combustion gases could be getting inside, particularly if a vent fan is running. The water heater could be defective and leaking gases on the inside, but I know the way my Atwood is constructed, and that's quite unlikely. Also, the CO detector should also be going off in those cases, maybe before the smoke detector.
These TTs are pretty leaky to gases, and any time a vent fan is running to reduce pressure inside, they start pulling air in through all the joints, crevices, and openings for plumbing, wiring, and accessory fittings. I would not at all be surprised to find that a super light TT like this one could be even leakier than most.
Now, if you had a LP detector going off, this is easier to understand. The smell of a dog will do that, as a LP detector is actually a total hydrocarbon device, looking for absorption of a particular wavelength by hydrogen-carbon bonds. People, dogs, cosmetics, foodstuffs can all put gases like that into the air, and the device has to be extremely sensitive.
Smoke detector is different, it is either looking for particles, or ionized gases from an early stage of "hot fire" combustion. Dogs might emit ionized gases in some small quantity, but not enough to trigger a smoke detector usually.
A bad or low battery will cause false alarms. High humidity will cause false alarms. A defective detector will frequently false alarm. Replacing the battery is a valid way to try to fix the problem, on the principle "try the least expensive solution first."
