Had the same problem as the OP. I'm used to the panning controls of SolidWorks. Which usually has no perspective applied to the view.
But in Keyshot, with Perspective on, every time I try to pan, it also rotates.
Once I turned Perspective all the way down, using Shift+Alt+RMB Drag to the right, I was able to pan, zoom ("dolly") and rotate ("tumble") as I am used to, to get the product into the right position. Found the perspective control in the K menu mentioned by thomasteger.
From now on, will turn the Perspective off, position the item, then add any perspective needed