Global y_array_get_random (const char *source_param_array): This doesn't really do anything that lr_paramarr_random() doesn't already do.
Global y_datetime ()
Global y_get_datetimestamp (): Use lr_save_datetime() or direct ftime() calls instead.
Global y_log_error (char *message): Forcing your error messages to get logged may not be the best idea there is. And I don't know of anyone using this, either.
Global y_log_to_report (char *message): Logging with a timestamp sounds useful, but I don't think it should be called "y_log_to_report()", and it is rather customer specific, too. Also, forced logging really should be it's own thing.
Global y_log_warning (char *message): Unused, and forcibly logging things even if logging is turned off is rather impolite to begin with ;-)
Global y_make_datetimestamp (time_t time, unsigned short millitm): lr_save_datetime() really should be used for this kind of thing.
Global y_post_increment_transaction_nr (): - y_increment_transaction_nr() does the same thing.
Global y_rand (void): Superseded by y_drand
Global y_rand_in_sliding_window (int lowerbound, int upperbound, int rand_max)
Global y_setup_logging (): This will probably be removed in favor of y_set_transaction_implementation(), which is really how this kind of extra transaction logging should be done. Note that y_transaction.c hasn't used the extra logging stuff in some time ..