For auto-correct, Launcher==>Settings-->Text Assist. I haven't played with the Touchpad enough yet to answer your first question, but Auto Correct was one of the first things I turned off (like I do on every device I own. )
I noticed after saving some photos from google image, the photo app would act weird. Instead of the photo, I got a small square. I used the file manager and deleted the photo manually. Saving the image as new wallpaper seemed to work fine though.