there is no way the clutch can affect the throttle cable. i'd say that the cable is either squashed from the install of the clutch, starting to fray inside the casing, or just got some gunk making it sticky.
and you shouldn't have to give it more gas to accelerate. you may have to give it more gas to launch the car as the heavier clutch won't slip as much, resulting in bogging it down, but once you are going there is no difference. and a heavier clutch doesn't really weigh any more than a stock clutch. it just has stiffer springs. it will weigh a fraction more due to the extra material needed to get the stiffer springs, but it is a tiny amount.
when they talk about the weights of clutches they mean the clamp weight. how hard the pressure plate pushes the clutch plate against the flywheel.