I'm really tempted to write a limerick in reply, but don't have the time right now.

Your car is completely normal. These cars have a "loose" torque converter and the engine idles at very low RPMs. As a result they have almost no "idle creep." It will just barely move on level ground, and anything that qualifies as a slope will cause it to roll back.

BTW, don't use the gas to hold in place when stopped uphill. Doing so can overheat the transmission and damage it. Use the brakes to hold the car in place.

- JimY