Possible Engine Mount Issue?

I have been experiencing a slight engine shake, especially at cold startup and when the engine shuts off during stops. I can literally feel the engine shutting down as the jerk is noticeable. Also, while driving the car has a feeling as if the engine was somewhat loose, don't know how to explain it, kind of like when a boat is in the water, you can feel the waves preventing the boat from a steady speed...it then speeds up then sorta slows down (that's the best way I can explain it).

My first instinct was going to be a bad torque strut mount that goes underneath the engine and holds it to the chassis. I saw multiple videos on symptoms when these go bad and that is exactly how the car feels. So, I removed it and to my surprise, it was in fairly good shape, no damage other than the normal wear on both rubber bushings. I do notice that I can wiggle the engine significantly with the mount on and obviously even more without it, could this simply be a design flaw or even with normal wear, the rubber's strength is weakened and thus causes this issue?

I was almost positive it was going to be the torque mount but now I'm stumped as I checked the right and left mounts and they also look in good condition.

Any suggestions?

 

If I remove the bottom torque mount, there's alot of wiggle about 1-2 inches of play but with it on, I can budge it with my own strength. I am used to engines that don't move at arms strength so this is why this catches me as odd and not sure if normal with these priuses. After spark plug replacement and injector cleaning, the car runs much smoother and doesnt shake as much at cold startup but I can still notice it slightly.