Hi Michael
While there is no restriction on the number of categories, this could create some page loading time issues. Unfortunately I don't have an example with so many categories. Also, the text “Filter by category” can be translated only globally (for all categories).
I would suggest that you used Minitek Wall instead. It is capable of handling many categories much more efficiently (by using static filters) and it also allows you to translate the “Filter by category” separately for each widget.