There seems to be a few clusters of possible re-openings, and I would suggest that all in each group be progressed at a similar pace to maximise the benefits from potential frequency enhancements etc.
- Aberdeen cluster (Newtonhill, Cove, Kittybrewster, Bucksburn)
- West Edinburgh cluster (Winchburgh, Newbridge)
Newbridge would be basically be a small town, on the peripheral of a large city, not big enough for a station, if it weren't for the M8, M89 and M90.
I'm not sure you could ever make it work, because pretty much anyone who would park and ride at Newbridge would either be served better by parking and riding at Uphall, Halbeath or Ferrytoll, or at Ingliston for the tram, or just getting a town from their local station in the first place.
Building it would likely actively encourage more people to drive for longer to get to Newbridge by car, and then take the train for a shorter journey. Its a really hard one to justify.
- Forth Valley cluster (Grangemouth, Cambus, Bannockburn, Bonnybridge, Abronhill)
Grangemouth is impractical, and never going to happen for many reasons above.
Abronhill, Bonnybridge and Bannockburn are because this area of the Forth Valley was hit hard by a combination of high numbers of closures in the 60s, and artificially high population growth in new towns in the 70s and 80s, often in similar places to the closures a decade and a half earlier. See also Aberdeen, and the government's failure to predict the oil boom.
- Fife Circle cluster (Dysart, Halbeath)
- Tay Valley cluster (Bridge of Earn, Newburgh)
- Kilmarnock to Dumfries cluster (Hurlford, Mauchline, Cumnock, Thornhill)
Realistically, any more stations need to wait for electrification and at least 1tph along this stretch, if only to make the sums work
I quite like the idea of a Livingston Parkway, with two platforms immediately to the east of Midcalder Junction. It would act as a sort of Motherwell equivalent for West Lothian and surrounds to allow direct access to WCML services without needing to go into Edinburgh.
Such a Livingston Parkway station would fail very quickly when you realise it would be very close indeed to Kirknewton, and as far as connections to the WCML, it would probably only be served by the 1tph stopping service on the Shotts line, and 4tpd? in each direction Carstairs ScotRail services.
Would splitting/joining at either Cupar (if the triangle junction was built) or Leuchars (if not) work?
Unfortunately, if it's not going to justify 1tph of its own dedicated services, it's very very unlikely to justify 1tph of splitting and joining, which is just going to be more complicated, would need additional units, more drivers, and would ultimately prove to be more expensive.