For what it's worth, never saw adding water as a sore point. When I see the level going down, I just crack the water valve open a second to add water into the loop inside the house. No need to fill from outside.
Next time I feed it more wood, if it's still a bit low, I give it a bit more. If I had to add 2 gallons all Winter, I would be surprised.
I think this is acceptable loss since I see steam from it occasionally just as the aquastat kills the fan when it reaches max temp.
As far as smoke, I don't think you can avoid it but can be reduced. I just crack the ash tray open to allow a draft if the fan is off. I have made the mistake of loading wood into it and forgetting to close the ash tray because of a phone call that interrupted my normal procedure.
So now, before I go out to load wood, I increase the temp on house thermostat to get the boiler hot. This reduces the smoke that would be sitting inside looking for the path of least resistance, which seems to be the door due to the baffle in the back of the boiler. With an active draft in process, it makes loading wood less of a smokey procedure. Sometimes I get treated to coals burning with blue flames. It kills me to add wood and drop the temp of the boiler but -20 temps require more fuel to make it through the night. Again, all makes sense to me and just had to learn its behavior and adapted mine.
All in all, have been very happy with my boiler. I am grateful for the help from many people here that have made the path energy independence from oil much easier.