Country is already covered by the country_name entries in the word table, so removing the country from the address vector will not change results but reduce the size of search_name significantly. Patch in names from OSM into the word table to make sure we have complete coverage. Note that bad entries still need to be removed by hand.
Empty relations may indeed appear, if the members of a relation have been deleted but the tags have been retained. That is detected as accidental error and the old geometry is retained in placex while the slim tables contain the new version without members.
Adds word counts from a full planet to the word table. There is a new configuration option CONST_Max_Word_Frequency which allows to take into account the word count: the value that was set on import is used to determine if a word is added to the search_name table. The value during runtime determines if a single term should be used for partial search or simply be ignored.
This manages to match up a lot more places and boundaries below city level.