Is there an easy way for me to set it up to just auto close the auto marked tasks without hotkey intervention?

Reason why I want this is because I have my home desktop, netbook, and work PC setup to synchronize my Firefox profile with dropbox (using NTFS junction links), and a lot of the time I'll leave whatever computer I'm on and forget to close Firefox so it can't sync properly.  It'd be great if this utility could be setup to auto close firefox after it's been inactive for some period of time without me being there.

Also, a whitelist would be kinda cool for this.