Any risks associated with habitually updating/reverting ALL features in drush? I want to start using drush commands to simply update all or revert all features (depending on which environment I'm in) instead of doing them one by one. What are the risks involved or questions I should ask myself before habitually just updating all or reverting all features?

drush fra (to revert all on production and test servers)

drush fua (to update all on dev environment)

Thanks!
In my opinion, first and foremost thing which should be taken into consideration is that your feature should not have any changes different from your development environment.

secondly, make sure that all of the fields of a content type have same type and widget as that are in your production environment.

You can also take backup of the db before reverting the features in case you are making any major changes.