I have always imagined that your father gave you the heir item saying something like "use this when the day of the great adventure comes, it will help you", or something like that. So at least personally, it doesn't hurt my immersion that it's not identified at the beginning. Upon entering the Chain is when my PC decides to finally use it and see what it really is!

I don't think any heir items have begun ided since forever (I still play on 1.1.1 occasionally, and I'm pretty sure they aren't ided back then either)

Agreed :)

Or your tower-dwelling sorceress mother. :p

Heir items are always blessed and some of them identify on equip (like 7LB bards get or any of the weapons/pieces of armor).
I think every other heir item should identify on equip, even if their regular counterparts in the game do not.

All heir items now are identified right away. IMHO this is reasonable, especially also to support less experienced our unspoiled players ;-)