With the manual you will also be able to safely EOC.
Taller gearing will definitely help you, especially on the highway. For me, at 70 MPH my RPMs are about 2300, and at 60 they are 1900. I know that the Manual Transmission for my car has ridiculously short gears (something like 2800 for 70, 2500 for 60, I'm not sure though) and that is why the EPA ratings are so much higher for the auto.
The A/C delete will help a ton, as well as the P/S delete. I know for me, just turning off the AC helped about 5-10% for my MPGs. When my Dad did turned off his A/C in his Accord V6 he got over 40 MPG trip. I'm not sure how much the delete will help (definitely a weight reduction and less of a temptation)