I've run into major problems reading PST files in Outlook 2011 for Mac, although they weren't related to the size of the PST. Outlook for Mac mangled some of the header information (sender name, etc), screwed up the formatting, and made it impossible to export the emails - they wouldn't upload to an IMAP or Exchange server properly. This was reproduced with several different PSTs from two different versions of Outlook for Windows. In short, I would never, under any circumstances use Outlook Mac to deal with PSTs if you care about the integrity of the data.
My solution was to use a Windows VM and a trial version of Outlook 2010 for Windows to sync to a free IMAP email account. Gmail worked decently although, believe it or not, I actually had the best experience with an Aol account. Aol uses standard IMAP while Gmail's implementation is a little non-standard.