Hi Jimmy, I have some low-draft issues too, the big problem though is that with almost no heat demand from the house, the water in my boiler gets pretty hot at times, I've had one instance of boiling so far.
I've been letting the fire go out in the mornings, and start it again in the evening, just to keep the chill out of the house on the 30-40* overnights. There is no way to make small enough of a fire to keep the water below boiling, and keep a fire going. If I had a stoker, I'd probalby be trying to figure out, like you, how to keep the fire idling during the day.
This morning is laundry day, so I've kept the fire going this morning to preheat the domestic hot water for the numerous loads of hot-water laundry.
I will probably use the boiler only a few more nights then shut it down for the summer. I have already started the work to build a good coal bin and improve my chimney this spring/summer.
Take care, Greg L