Last time I worked with a scroll wheel, moved the character according to how far the scroll wheel was moved. However I found it really inconsistent between scroll wheels as sometimes a mouse would make the character way too fast. The way I implemented this time was that every frame the game would check if you moved the scroll wheel up or down and move the preview forward one space or backward one space. I thought this would fix the issues because as long as the player is moving the scroll wheel each frame the preview would move regardless of how much the scroll wheel is changed. I'm not completely sure but maybe it had to do with frame rate because the scroll wheel would be checked every frame. I have theoretical two solutions right now: move according to how much the scroll wheel is moved but cap it or exponentially increase the speed depending on how long you've been scrolling.
The camera panning was definite new to me too. I added it to make sure the game gave me enough space to design levels without being to large. I tried to make is as smooth as possible as the cameras would move faster the closer you are to the edge of the screen with a linear increase. I was going to try to implement a exponential relation but thought it was too much work you too little results. By variable zoom should I add that to a settings menu? I will try to fix all these issues once the rating period ends. Thank you for the criticism.