Can you make your own custom rules in Check?
No, it is not supported to create/add custom rules to the Check.
Is it possible to centrally manage the level of warnings of the different rules as well as enabling/disabling some of them for all our users?
No, it is currently not supported to centrally manage the Check settings.
Can Check detect wrong spelling for specific words? For example, I would like my company name to trigger a Check warning if it’s being misspelled?
No, it is currently not supported.