Regarding your questions:
1. Whatever is put in the filterable configuration object will override the kendo.messages.xx-XX.js
configuration. In other words if you would like to customize the operators through the filterable configuration object you will have to also handle the translations.
2. Kendo culture can be changed at runtime through the culture method
. It is important to note that the corresponding culture files should be loaded before kendo.culture is executed. The messages files work in a different way - they modify the default values of the messages in the widget's prototype object. This is why in order to change the widget messages you should at first load the file and then re-create the widget. We prepared a code library project which demonstrates how this can be done.
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