10k miles seems fine given:

1. What steps did you take to get the two PNR's linked? Did you check whether they had been linked? What was the argument about baggage and seating at check-in? With the latter, was it that you couldn't sit together? Checking-in online may well have solved that.

2. Associating two PNR's won't automatically sit you next to someone (but I suspect you know that), did you check online / over the phone to see which seats you had both reserved?

3. Did they know for sure at time of booking? Was it a regular event by then, if so, I agree they should have told you.

4. That's as much LHR, or any large hub as it is BA. It doesn't happen in MUC or VIE but then LH and OS don't have a WT+ cabin.

5. Worth some compensation.

6. Again, worth some compensation.

7. I don't believe staff should lecture passengers, but one person's lecture is another person's explanation. On the other hand, the person did bend the rules for you, so I'd call this a score draw.

8. I've read that sentence several times but genuinely don't understand what the problem was. You are a Gold card holder traveling WT+ so could use the Arrivals lounge. Are you cross that it took 15 minutes to find it?

9. If someone on the phone confuses you, ask them to explain it again slowly or email you. Seriously, it will save this sort of annoyance in the future. You mention not being able to sit with your colleague, perhaps we could have some more information to see if this was BA's error or your error in understanding the rules.

So, 10k miles for problems with your IFE. That's fair.