I'm not aware of any issues with customers using
WordPress Multisite, but our themes are all compatible with the latest WordPress version.
AppThemes does not officially support third party plugins, so therefore they are not generally part of the testing process which would allow us to come up with a definitive list of those that do not work. We have recommended plugins on our
Resources Page, but outside of this list, we do not make guarantees about any of them (even though there are many which DO work fine).