Huh, that option must not be in X3

. I use X4 (after upgrading from 9 which of course didn't have it!!!), and the pic below is where my option is. If it isn't there, it evidently doesn't have it. Also, control panel changes the "universal" computer mouse settings. Corel overrides those.
On the text size thing, try this (again this is X4, I assume the option's there

): Text --> Character Formatting opens up the docker. With NOTHING SELECTED (important), drag or type the text size in the docker. The popup should come up to apply this as default to artistic, paragraph text, or none.