I find that the weather radar works best on the lowest distance setting, I think it's 20 miles. It also only shows the clouds directly in front of your aircraft so if your cruising with a 3 degree pitch up, it will only show clouds that are 3 degrees pitched up (if that makes since)

I find that if I setthe heading hold first until I have intercepted the GPS track (on Nav1) then change to Nav/Loc on the auto pilot that it follows the GPS fine.

Lastly, don't use EPR to set your takeoff thrust, set N1 to about 104% for takeoff and 94-98% for climb. The EPR setting aren't accurate.