Hmmm I dont see vacuum leak on your list.
Dont underestimate the degree to which a vacuum leak can cause running issues on these cars. They are also extremely elusive to locate.
Smoke test, vacuum gauge, slightly pressurizing the intake are all methods to identifying this issue. Lots of general information on youtube which could apply across makes and models as well. I had the vacuum line disconnected from under the intake once and the car would not run or idle. Reconnected and the car ran perfect.
Info on the ICV:
https://www.clarks-garage.com/shop-manual/ts-01.htm (see engine idle surges section)
https://www.clarks-garage.com/shop-manual/fuel-21.htm
https://www.clarks-garage.com/shop-manual/eng-15.htm
O2 sensor another possibility but I doubt thats the issue.