Maximum # of rows? Characters? Attachments?

I sometimes make extremely lengthy outlines, jam-packed with attachments, and am wondering if there’s a limit to the number of rows, or words, or characters, or attachments, etc.

I’m guessing not, but thought I’d ask.

Not sure. I looked in the user guide, release notes and product page and none of them mention file limits. It’s possible that the limits are whatever the file system/OS limits are but you may find that the file gets sluggish after a while.

You could always email support (Help > Contact Omni) and ask them.