Bill,
Make sure that line is unregulated or the Buddy won't heat. I tried to use my stove port on my Niagara but it doesn't generate enough pressure. Some one tried to explain how single and two stage regulators work but I am still kind of fuzzy on it. Basically I got that ,if you have a device that requires tank pressure it will not work or work properly if the pressure is below a certain point. Don't remeber what tank pressure is. I know that at my house we have a gas pack, LP. They stepped the tank pressure down to 2 psi, then stepped it down again at the unit to something like 1/2 psi. Also I would highly reccomend that you leave a window cracked for fresh air, and add a CO detector. Never can be too safe.
As far as filling small LP tanks from the larger ones, 1) it does work, but the tanks never get as full as they were orginally. 2) We used to put the small tanks in the freezer overnight, it seemed to help pull extra LP into them. 3) It is illegal to transport refilled 1# tanks. I'm not going to tell. The only other odd issue is every now and again the valve on the 1# tank will fail and you will need to toss the tank.

Aaron