What are the downsides, if any, to creating a new identity in Outlook 2011 as a quick and dirty method of using the existing identity as an archive?

For years, in Entourage, I created a new identity each year for all my mail ("2009 Mail," "2010 Mail" etc.).  If there were folders that I wanted to keep working with containing prior work, I'd just drag that folder to the desktop and import it back into the new identity.  To access old mail, I'd just change identities.  This worked extremely well for me.

In Outlook, I just never got around to it.  I now notice I have 25,000 messages over three years in my inbox and probably 50 folders, many of which are no longer regularly accessed.  So I'd like to revert to my prior practice of creating a new identity for 2014 mail.  I would be unlikely to access the old identity more than a dozen or so times a year, but that's enough to make plain vanilla archiving awkward.  (I am aware of programs like EagleFiler and may try it.)

Am I asking for trouble?

Further info:

OS 10.6.8

iMac 12,2

Outlook 14.3.1

Single home office computer, no security issues

I run no schedules

I don't mind using Microsoft Data Base Manager to change identities

Thanks for any advice