Hello again vase
As regarding the DUB route you will not require a stop over as all the DUB bound flights from any US airport (LAX, ORD, BOS, JFK) leave in the evening and therefore arrive in the morning and you can easily make a connection in DUB to EDI

As regards the EI J service it is great I did it a while ago and there is full reports of it by other FT'ERS on FT trip reports and in the European FFP forum

Then for the OWE business class ticket there are selling here in Dublin for about $4500 so it is my understanding that it is possible to book it here with AA and pick your ticket up in the US. But I have not heard anyone doing this but the AA agent I spoke to told me that I could do this when I enquired about the “I” sale on AA that was recently posted here

There is also an other option available you could just start your OWE in YVR and fly to LHR on BA would I be correct in this assumption and just buy a return ticket to YVR from SNA so your could do YVR-LHR-EDI-LHR-HKG-YVR or something like that the later being on BA or CX, or you could create a long route using all the flights coupons available on a OWE to earn miles and status on your way home. As for the not earning AA miles on BA as you said earlier you have no status on any OW airline so you could join BAEC or MPC but as far as time goes to get to EDI the DUB route is quickest and less stressful

Regards

IFB