Don't move mouse or press mouse buttons - if you move mouse to some area where script is getting checksums, then it will not recognize checksum and may exit with error.
Don't press any keys - although the script tries to intercept some dangerous keys that may accidentally close abilities selection page, it is still better to not press any keys.
If you want to get strength higher than certain value and at the same time get good overall ability score, you can set impurity limit to some value around average impurity for current character minus 10, and set strength limit to desired minimum strength. This way, script will not waste time looking for strength in combinations with low overall ability score. And it will not switch to combination with better ability score if strength is not good enough.
Before rolling abilities for character with complex strength value, it would be better to learn strength values first by setting strength_limit=1 and rerolling abilities until all different strength values are cached.
If you try to run script for different version of the game and it seems that controls are placed differently on abilities selection page, you can find FillCoordinates function in the script's source and place case for the title of your version of the game, where you can set different values for controls. You can find coordinates using "AutoIt Window Info" utility from AutoIt, after setting Coord Mode to Window.