You may know that Outlook is essentially a huge database file, and as
such it readily imports to Access, and from there to Excel if you
still need to go that route.

If you'll open up a blank database file, select the Tables tab along
the left margin;from the menu click ~File ~Get External Data and
select Link or Import as you like. You'll be prompted for a file
location (on my machine my Outlook PST files are in a folder called c:
\mail but yours may be different) and also for "files of type": select
Outlook. From there you'll be prompted to specify Tasks, Mail, etc.
Tasks are located in Personal Folders.

I suspect this will solve many of the problems you've encountered,
although it may still bear some experimentation: importing is
different than linking, and may provide different results. If you
import, for instance, you can select data types for the fields you
import, and use Memo type fields for the Notes to accommodate long
text strings.

Good luck with it- please let us know how it turns out!