Ulama observing pardah from non mahrams and keeping a distance from non-Muslims

Perhaps what they mean is that Ulama who qualify from Darul Ulooms like to observe pardah with non mahram women and they don't like communicating with non mahram women unnecessarily. This approach conforms to the Islamic teachings and there is a lot of safety in this for one's imaan and self respect. Similarly, it will safeguard oneself from people having suspicions regarding them.

Similarly, they don't like to have close communication ties with non Muslims as a believer is not supposed to be close to the disbelievers. This approach conforms to deen as becoming close to the disbelievers can cause one to become influenced by their culture, dressing and ways. Therefore, it is best for a believer to keep a distance from disbelievers.

And Allah Ta'ala (الله تعالى) knows best.