You will get different opinions on what to tune in what order, but this will get the ball rolling for people to judge.
A) In D A/F ratio (auto)
B) Cruise A/F (20mph to 75mph or so)
C) Light to Medium Accleration (no secondaries)
D) WOT

""Truck does not seem to like idling cold.""
- Try mid 12's on initial cold start, then is should creep up to your N A/F reading in the mid 13's as it warms up.

""Once it's warmed up and idling in park at around 750rpm (16" vacuum), I'm reading right around 13.5 on the O2 gauge.""
- You will find different opinions on what is rich and what is lean. What I have found out is that you must first find out if you are running gasoline, E10, or E85. Once you know this, then you will have a reference as to what your stoich should be. The 13.5 is a good start on your N reading but the more important reading is your in "D" A/F since you have an auto car. Once you have the "D" A/F reading where you want it, then your N A/F reading will be whatever it is. I have found it to be slightly richer.

""In gear, idle drops down to ~675 rpm and the O2 gauge has a slight increase to around 13.8-14"".
- This number looks good too as long as you have your highest vacuum reading at this A/F reading. Just tune for the highest vacuum reading in D and then reference the A/F reading.

After you have the in D A/F worked out (which you are fairly close arleady), then work on your cruise A/F number (B above).