I wouldn't worry about these two errors:
Code:
sysdeputil.c:1112: warning: `vsf_insert_uwtmp' defined but not used
sysdeputil.c:1151: warning: `vsf_remove_uwtmp' defined but not used
all that means is in the source he (the author of vsftpd) has defined a couple of variables but then never assigned a value or used them later on, alls it does is waste a little bit of memory, a few bytes depending on the type of the variable.
The other error I would be a little more concerned about, and I would keep a close eye on vsftpd to make sure its working correctly for the first few days