Difference between transform and location?

Adding to this answer, explicitly addressing the rest of the question, GetActorLocation() returns the same as the Transform.GetLocation(). GetActorLocation is a convenient way of just getting the location. This code:

        FVector VehXYZ=CurrentVehicle->GetActorLocation();
        FVector altvxyz= CurrentVehicle->GetTransform().GetLocation();
        UE_LOG(LogTemp,Error,TEXT("VehXYZ is %s"),*VehXYZ.ToString());
        UE_LOG(LogTemp,Error,TEXT("alatvxyz is %s"),*altvxyz.ToString());

produces the following output:

LogTemp:Error: VehXYZ is X=99.992 Y=1000.147 Z=14.511
LogTemp:Error: alatvxyz is X=99.992 Y=1000.147 Z=14.511