well i've got one now...
we've had ours for about 7 or 8 weeks now, she is a 4 year old foster child. we are her 5th care takers!! when we got her she was WAY over weight (has lost about 15lbs already and looks great now!) an as you can imagine, she was a nervous wreck! she was house-trained, but she didn't care. all that meant was that she new when she was wrong, doh! she's become one of the family though and is doing quite well.
HOWEVER to answer some of your questions... we have a large detached garage that we keep her in when we are gone... just don't trust Lilly in the house by herself, she likes garbage. she has been in there both w/ and w/out a coat. She does fine both ways, but since she never fights putting the coat on, and never trys to take it off herself, i put it on whenever possible.
i can't answer the less exercise question because she was so fat before from never doing anything. even the last people who had her said she hated the out doors. she only went out when nature called, then ran back in. she still does that, but now loves to go out on the farm with me, so she gets lots of exercise.
that said... the regular food we have for her suggests around 2 to 2 1/4 cups a day for her. so i give her 3/4 cups of dry dog food in the morning with a warmed up 1/2 can of dog food mixed in. she loves it and it doesn't look like she is gaining or losing weight anymore so i think the mixture works.
I think Lamb and rice is a good rule of thumb, but from what i've experienced, and read, and heard, i think most important is just making sure your Dal always has access to water and can go to the bathroom when needed.