[eluser]jedd[/eluser]
Well, I could go through and summarise all the questions that are pending - and all the ideas that could do with your comment - such as what error-reporting means in this context, whether you have a security/authentication system wrapped around your app already, how secure do you really need this stuff to be, how precisely timed the tasks need to be and how long they'll take to run ... but it seems easier (for me) if you'd actually just look through what's been asked / suggested, and then answer / comment.
I guess we can now add to the list:
o do your required regular tasks match extant controllers' functionality,
o if not, how complex are the things you want to do (say if you authored a non-CI, or even a non-PHP script to run them).