Is an Outlook .PST file of 2gb too large?

Which version of Outlook are you using? The older versions (Office 97, I think) did have file corruption problems with large .PSTs. I thought they had fixed it with the more modern versions, though.

It may not be a bad idea to split some emails off into another .PST.

Be sure to compact the pst file to cleanup and minimize size.

As @mrentropy mentioned, file max size issues were fixed. to the best of my knowledge

However if you’re just collecting everything in your default pst, you may have performance issues. Best to archive stuff – say, older than a year – off into one or more secondary files. Just create a new Outlook Database File, and drag and drop old contents to it.