Considering that Mays and Frank, as well as Koufax, Ryan, and other respected stars are still alive, I don't think there's any better answer than Aaron both for his accomplishments, the adversity he overcame, and his conduct. Mays was the better player, and Robinson had leadership positions after his playing days, but it still comes down to Aaron.
As for this team, I'm not going to be cute and say Vladi / Hawk / Carter
, so I'll agree it has to Frank.
Most respected all time? Wow, tough. Wagner and Matthewson in their day were thought of as moral giants as well as accomplished players, and I'll throw in Greenberg and Clemente as groundbreakers, but it still has to be Jackie.
Washington baseball, in history? Johnson, hands down. I dont' really associate Gibson with Washington as much as Pittsburgh, and I think his personal life probably knocks down some of the respect he is due. Killebrew's association with this city and his accomplishments here are almost a trivial part of what made him a HOFamer. Nice guy, too, but not Mr. Washington Baseball. If you say Killebrew, then you should probably say Ted Williams.