Panning is tricky, and the primary reason that I'm thinking of abandoning the spark. I believe it's the two axis gimbal that is the cause. I've owned a Phantom 3 Standard, and still own a Mavic Pro. Both of these pan beautifully because of the three axis gimbal. You still have to be careful, but not hyper careful.
In addition to tripod mode, consider flying in P/GPS mode leaving the obstacle avoidance enabled, and reduce the stick sensitivity. This will slow the already slow 6.5Mph obstacle avoidance enabled speed, but will reduce the sensitivity of the left yaw stick. If you are flying close to objects, or low to the ground 6.5 mph is tolerable.
Also, you don't have to pan. I've studied many of the Spark videos by 'famous' videographers, and they NEVER pan. They rise up, drop down, fly forward while descending (personal favorite), rise up while flying backward (watch for trees), move left to right (rarely). Generally, they fly close to objects, low to the ground, and reveal their subject in layers e.g. rise up from behind a large object to fly by the revealed object to reveal a third object.
They NEVER pan.
Myself, I love the pan look, and with the spark it is a real challenge.