Little bit out of my area. Whenever I see the repair was "new nozzle & ignitors" I'm always skeptical. The problem wasnt found, and the issue wasnt fixed. "It is flowing more oil into the furnace than needed(tech's words)." is about the worse, most uneducated answer I've ever heard. I don't even know what that means. Unless the heat exchanger is cracked, it can be repaired. Sure 1986 install & 71% efficiency are more then enough reason to replace it.
You really do need someone to come in and give the whole system a look over, and possible re-design, especially regarding the ductwork and airflow. Any furnace chosen wont fix those problems.
You didnt say if you had/or are going to install AC. One possibility (if a competent professional agrees) repair furnace for backup, and install a mini split. This was done at my helpers house (Philly suburbs) and he didnt run the furnace at all this winter.