Hi All
I struggle to find out what I may / may not be entitled to claim in this particular case, so I hope someone can help :-)
Itinerary in question: I was flying the return of a BA Holidays booking: PDX to LAX (BA op by AS) > LAX to JFK (BA op by AA) > JFK to LHR (BA) > LHR to JER (BA) - Dep from PDX on Sat 26th Aug at 7:20am from PDX, arr in JER on Sunday 27th at 4:35pm

What happened: 2 disruptions occurred:
1/ my LAX to JFK was showing very late, and GGL kindly rerouted me via IAH, keeping the TATL in First, so that I could be on the original final leg to JER (well done BA for this) - the change was done Saturday morning
2/ My new travel itinerary went very well till LHR.
3/ At Heathrow yesterday the final flight (LHR To JER) which was supposed to depart at 15:30, was shown successively as late departing at 16:24, then 17:24 then 19:25, then as finally cancelled.
Not sure if this is relevant but there were two LHR to JER flights departing after: they all departed '' on time '' (next left 32 min late and arrived 22 min late; last one left 3 min later and arrived on time)
4/ when enquiring with the CCR staff, staff could not understand why my flight has been suddenly removed from all information screens at around 630pm (which was odd), but were able to confirm the flight was cancelled, and were able to put on the last flight (dep 19:40, arrival on time in JER at 20:45)

Where I could do with help :-)
a/ if I am due compensation, is this a long-haul category compensation or a short-haul compensation? (noting I had an initial rerouting in the US. was travelling on BA from Houston - IAH, but also the issue leading to delay appeared on the last leg (BA to JER)
b/ Unclear about the exact reason for the cancellation of BA1346 LHR to JER on Sun 27th Aug. Should I assume it is not weather or ATC-related given the next two similar itineraries were flown on time? At worst it would be a knock-on effect so likely still to be eligible for EU261?
c/ in your views should I be eligible to claim compensation and if yes how much?

Thank you All