In re: Hosts, Guests & Catering.

Catering is a specialised line of work which every restaurant CANNOT successfully venture into. 

Many good restaurants run HORRID catering operations. 

THAT SAID even with such HORRID catering operations, greater DILIGENCE by HOSTS can SALVAGE events to some extent.

PS: Blacklisting Guests is common practice. However blacklisting hosts is often necessary for relative health & relative happiness.