Ming at #47, Bosh at #50 and (especially) Ginobili at #71 are steals. With the players you do have, I'd try to move Allen or Q while their value is up.
Garnett - PTS, REBS, FG%, FT%, ASSTS, BLKS
Arenas - PTS, STLS, FT%, ASSTS
Allen - PTS, 3PM, FT%
Bosh - PTS, REBS, BLKS, FG%, FT%
Ming - PTS, REBS, FG%, FT%
Ginobili - 8-cat.
As you can see, Allen is very exependable with Q on the roster. Your frontcourt's FT% is good enough that you're wasting Allen and his FT% - a sexy stat that will draw any possible suitors to him.
As for the Williams/Livingston/Telfair situation, I'd try to trim the fat off of your team and pick up Telfair. He could be a monster cat guy with the opportunities he's about to receive.