Office Online questions

I just started looking at Office Online as a way to allow my small
firm's employees to have shared access to calendars. I have two
questions I was hoping someone could answer:

1. Is Office Online compatible with Outlook 2003?

2. In Outlook 2007, once I publish my calendar to Office Online, and
then the other employees subscribe to my calendar and add it to their
Outlook on their computer, is there any way that I can grant those
other users write access to my calendar? In other words, can Office
Online be configured to allow other users to add appointments for me
under "Josh's Calendar" in their Outlook, then have those new
appointmens sync to the server, and then back to my original calendar
on my desktop?

If we can't do #2, is anyone aware of a way that my three-person firm
can set up shared read/write calendar access so that each employee can
read and write the calendars of the other two? Someone suggested
Office Live. Will that work?