limit - This optional attribute allows you to select how many tweets are displayed. Only accepts values 1-20, anything over 20 will only show 20 items. Anything less than 1 will be ignored.
aria-polite - This optional attribute is primarily for users that are using screen readers to use Wikia. Depending on how you set this, users using these technologies will be notified if a new tweet comes in. Legal values are
off - user will receive no mention of it updating
polite - user will receive mention when they finish what they are doing
assertive - user will receive mention as soon as possible
The Twitter box can be customized, but the customization is limited. Within Twitter's widget setup, you can change the height, theme colors, and link colors. The rest would have to be changed via local CSS on the wikia.
Twitter's widget creator doesn't honor the width value on the left when creating the code. If you wish to add a width or height value, you can do so by adding it to the link manually like: