The information you sent looks fine, but you are still getting the message: Error: Unexpected token or statement in file '/usr/local/nagios/etc/checkcommands.cfg' on line 49
if so this is a syntax error in the checkcommands.cfg. Look at the checkcommand on line 49 in your check commands file somewhere in that checkcommand is an error. Nagios is pretty picky in regards to syntax. I was looking through the defauld installation and I could run the nagios process from these. My commands look much different than the ones you posted:
'check_tcp' command definition
command_line $USER1$/check_tcp -H $HOSTADDRESS$ -p $ARG1$
'check_udp' command definition
command_line $USER1$/check_udp -H $HOSTADDRESS$ -p $ARG1$
'check_ftp' command definition
command_line $USER1$/check_ftp -H $HOSTADDRESS$
Also I remember having problems when there were blank spaces on lines. I tried to comment stuff out but left spaces in front of the # and recieved syntax errors.
I would suggest to setup small test commands/services/hosts so you can have minimal problems getting the initial app to work and then master it. You will notice that nagios configuration is repetitive and once it works once, you will be able to add on to it easily and identify problems as you go.