You can't do billing because Project is a work planning tool, not an
accounting tool, a time and billing tool, nor a personal time management
tool. It's designed to help the person responsible for defining the work to
be done by a team of resources and coordinating their work, scheduling their
activities so that they meet a specific, defined, time-limited goal. It
care's about how you get the work done, not whether you get paid for it -
that's the job of other tools.
You are mistaken when you say it breaks Outlook. I have both Outlook and
Project installed on this computer I'm typing at right now and both
applications are working just fine, including Outlook's task and task
assignment tools. If you're referring to Project's Workgroup Email task
assignment tools that interact with Outlook - true, they were removed from
2003 in favour of the Project Server solution but can be restored with only
a little effort - all you needed to do was a minimal amount of research on
how to obtain, install, and use them properly and your problem would have
been solved.
Lord knows, MS does enough stuff wonky that they don't deserve badmouthing
for things that they haven't screwed up.