The warnings and notices should not prevent httpd from starting. Do you not see anything reported as an error in the error_log for Apache or your messages file?
You can try to run the following to get as much info as possible:
sudo apachectl -e "debug"
Pipe it to less/more or redirect to a file as you will get ALOT of info.
LogLevel adjusts the verbosity of the messages recorded in the error logs (see ErrorLog directive). The following levels are available, in order of decreasing significance:
Level Description Example
emerg Emergencies - system is unusable. "Child cannot open lock file. Exiting"
alert Action must be taken immediately. "getpwuid: couldn't determine user name from uid"
crit Critical Conditions. "socket: Failed to get a socket, exiting child"
error Error conditions. "Premature end of script headers"
warn Warning conditions. "child process 1234 did not exit, sending another SIGHUP"
notice Normal but significant condition. "httpd: caught SIGBUS, attempting to dump core in ..."
info Informational. "Server seems busy, (you may need to increase StartServers, or Min/MaxSpareServers)..."
debug Debug-level messages "Opening config file ..."
When a particular level is specified, messages from all other levels of higher significance will be reported as well. E.g., when LogLevel info is specified, then messages with log levels of notice and warn will also be posted.
Using a level of at least crit is recommended.