(2)No such file or directory: AH00104: unable to start piped log program

You'll find it easier to configure logrotate to do the rotation for you. If you create a file called /etc/logrotate.d/php containing something like the following, it'll handle the log rotation automatically. This is just a guide, so make sure to test and customise it before you put it into production.

/path/to/php.log {
    daily  
    missingok              # don't rotate if the file isn't there...
    notifempty             # ...or if it's zero-length
    rotate 30              # keep 30 days' worth of logs
    compress               # gzip the logs, but...
    delaycompress          # ...only after they're over a day old
    create 640 root adm    # permissions with which to create new files
    sharedscripts
    postrotate
        /etc/init.d/apache2 graceful    # or whatever makes your process let go of the log file
    endscript
}

NB: the comments in this extract break logrotate syntax, so make sure to strip them out of your live config file.

You are missing the apache2ctl script and the symlink for apachectl. For Ubuntu 14.04, both should be in the /usr/sbin/ directory with the following dates (normal installation, upgrades) and permissions:

-rwxr-xr-x 1 root root   6402 Jan  3  2014 /usr/sbin/apache2ctl
lrwxrwxrwx 1 root root     10 Jan 14 17:46 /usr/sbin/apachectl -> apache2ctl

If you have a backup of your system, you should recover. If not, you will need to repair the Apache2 installation.

NOTE ALSO: The /usr/sbin/ directory is a shared directory holding all scripts generally accessible with root privileges. Given that you do not know how the apache2 files went missing, you could have problems beyond this issue or even beyond apache2.