frequent-cron: always permission denied, even after chmod 777 - linux

Question

I've installed frequent-cron, according to the installation instructions on https://github.com/homer6/frequent-cron.
I've changed /etc/init.d/frequent_service/init_script.tpl for my own needs:
# This is arbitrary. Change it to whatever you'd like.
SERVICE_NAME="frequent_service"
# Frequent cron must exist at this path. Optionally, you can change it to a path where it does exist.
EXEC=/usr/bin/frequent-cron
# Change this to the path of your choice.
#PIDFILE=/var/run/${SERVICE_NAME}.pid
PIDFILE=/var/run/${Odoo_OPC}.pid
# Point this to the shell (or program) that you'd like to run. /tmp/myshell.sh is just an example.
#COMMAND=/tmp/myshell.sh
COMMAND=python /usr/bin/OPCConnectie/OdooNaarOPC.py
# Frequency is in milliseconds. The command will be invoked every frequency interval.
FREQUENCY=1000
But when I want to start frequent-cron with:
sudo /etc/init.d/frequent_service start
It gives these errors:
hew#hew-VirtualBox:~$ sudo /etc/init.d/frequent_service start
/usr/bin/OPCConnectie/OdooNaarOPC.py: 1: /usr/bin/OPCConnectie/OdooNaarOPC.py: import: not found
/usr/bin/OPCConnectie/OdooNaarOPC.py: 2: /usr/bin/OPCConnectie/OdooNaarOPC.py: Syntax error: "(" unexpected
Starting frequent_service frequent cron...
/etc/init.d/frequent_service: 32: /etc/init.d/frequent_service: /usr/bin/frequent-cron: Permission denied
frequent_service started.
Even after:
sudo chmod -R 777 /usr/bin/OPCConnectie/
sudo chmod -R 777 /etc/init.d/frequent_service
It gives the same errors.
I think I can split this problem in 2 problems.
1) Error about the python script:
I don't know what's wrong because it runs fine in a normal cronjob.
Is there anything wrong with how I want to start the script in init_script.tpl?
2) Error Permission denied:
I always thought chmod -R 777 gives the folder + all subfolders and files ALL permissions? So why permission is still denied?
Edit: Checked the permissions as exussum recommended:
hew#hew-VirtualBox:~$ namei -m /etc/init.d/frequent_service
f: /etc/init.d/frequent_service
drwxr-xr-x /
drwxr-xr-x etc
drwxr-xr-x init.d
-rwxrwxrwx frequent_service
hew#hew-VirtualBox:~$ namei -m /usr/bin/OPCConnectie/
f: /usr/bin/OPCConnectie/
drwxr-xr-x /
drwxr-xr-x usr
drwxr-xr-x bin
drwxrwxrwx OPCConnectie
Are these correct? Or, should these permissions be enough?
Edit 2: Answer to problem 1 (python)
Had to put the following line on top of the python script:
#!/usr/bin/env python
Found here: Crontab wont run python script
Still need permissions for /usr/bin/frequent-cron though.

Answer 1

It's likely you don't have permission (x) on one of the paths leading to it.
namei -m /your/path/here
will show all permissions of the path to that point.
Edit
On second look looks like your missing a shebang line
#!/usr/bin/python
at the top of the file.