Thanks, yeah I must have looked at some odd site to give me the wrong terminal info. As BA just confirmed with me on the phone it's T5 the flight arrives at.

Yes, t5 is usually quite efficient. However much depends on the arrival of your inbound flight. However if al one ticket, BA need to put you on the next available flight with seats, if you miss your one, that may be the next day or whenever.

But if this really is your only option, then it's your only option, it's definetly doable barring any hiccups on the day with the inbound.

Yes, it will be enough time, just follow the signs for connecting flights and as it's a through flight booked on one ticket if you your incoming flight is late and you miss the connection they'll put you on the next available flight.

Are all the ex-BD rotations from EDI definitely in T5 now?

The ones I checked yes....but OP can do the same

I doubt the booking system would allow a 70 minutes connecting time if a terminal change was required... Anyway Alan confirmed it will be T5 to T5. So no particular issue: 70 minutes is enough ... unless of course the inbound flight is very late (I think 45 minutes is the absolute minimum connecting time at T5)...