Can Outlook appointment items be accessed via Linq?

I have a class which allows me to read and write Outlook appointments either locally or on an Exchange server. This class uses COM Interop to drive the Outlook object model.

It works, but is pretty slow when reading multiple users' calendars from Exchange.

Is there a way to read this data using a Linq query or ADO? I have read that CDO is not supported in .Net. I could be wrong on this though.

Another question: when I read this data from Outlook, I fire off a separate thread for each user's calendar. Each thread constructs its own Outlook Application object and reads the data. Would I be better off creating a single Outlook Application object and passing it to each thread instead? Seems to me this would blow up rather quickly, but I'm no expert. Thanks.

Using .Net 3.5SP1