Sometimes the GEDCOM imported from other programs has Note fields saved in Note Records, even when they only have a solitary link, and could be Local Notes
Many other programs allow arbitrary formats for dates, that Family Historian will often interpret as Date Phrases, which can easily be recognised as they are shown in quotation marks
Sometimes when importing GEDCOM from other programs the Record IDs get renumbered sequentially from 1, but you may wish that they are retained unchanged