Depends on the cash situation tbh.
I would try and get the airbag light done as a minimum before selling either way. Checked connection and cleaned the contacts under the seat? If so then it should be a case of using the right software to reset the light. Have a search on here for tips, plenty of old threads on this.
As for the floppy handle thats an easy fix. Remove the door card and fix or replace the spring (more than likely the culprit). Will take you only a couple hours max.
As for the other work I would do it if I could afford, otherwise be prepared to take a little hit on selling price.
To err is human, but you need an Alfa to really screw things up!
The road to heaven is paved with old Alfa's.