The appearance options control the appearance of the meta search results pages. Currently the Results Authorization and query options of the meta profile do not apply: use the target profiles' options instead.
When using best bets the meta search profile must have the same group names as the backend profiles. Any best bets from the backends that have group names that are not defined in the meta profile will not be shown.
Query logging of the meta search and the backends are independent of each other. The meta search will respect its own query logging setting as will each of the backend profiles. So it is possible to have multiple logs for the same query if both the meta search and the backend have query logging turned on.