i don't think so, Bethesda are concentrating on fallout new Vegas now !
Broken Steel Mothership Zeta Point lookout The Pitt Operation Anchorage
yes
Got milk
Broken steel is already in the regular fallout3 except for Mothership Zeta, The Pitt, Point lookout, and Operation Anchorage.
for pc, yes. for ps3 and xbox360, no.
by killing an brotherhood outcast npc.
fallout3 IGN goty
usually someone will just drop it.
you can get another dog if you have completed the broken steel add on, and have chosen the perk "puppies!" which gives you one of dog meat's "puppies." even if this dog died it will be replaced with another "puppy."
you find it northeast of mdlp power station
yes.
Its a quest but i don't know which one, try looking walkthroughs on youtube.