Hi larsemil
I'm by no means an expert on this board, but i'll do my best to answer your queries until anyone more knowledgeable comes along to answer.
To answer your questions in order:
1 - Its my understanding that you can check-in online before your flight without having to print your boarding pass. You can then get your BP at the airport when you are checking in (with the added bonus of still being able to change your seats if something nicer has opened up since OLCI). Dont forget that if your flights are all on the same booking, you should be able to check-in online for your LHR-JFK flight at the saem time as you book in for your CPH-LHR flight.
2 - Your best bet is to check specialist sites such as
Seat Expert or
Seat Guru to find out about what the "best" seats are. Going by the fact your LHR-JFK-LHR legs are on the 747s its a safe bet these will be the High-J configurations with 70 business class seats. However, given you are economy (WT), i dont think this will have much bearing on your layout.
3 - You can check out loads and available seats on sites like
Expertflyer, but i think you need to pay to subscribe to these sites to get the info you want. Alternatively, the BA board is pretty helpful and some nice soul on here might get a note of the seat maps for you.
4 - You'll have a couple of choices of meals in economy, but as for what these will be there is no way to know before you fly, unless a member of BA cabin crew on the board can provide you with the information.
5 - I dont know the answer for this one for sure, but i would think the answer would be yes as i dont imagine you are clearing UK customs but are merely in transit.
6 - Just follow the signs for "flight connections" and these will guide you to the busses that will take you from one terminal to another.
7 - Again i'm not an expert here, but i think Q is a discounted economy ticket, which means you will be entitled to 25% of the miles for these flights and no Teir Points. You can find out how many miles these routes will yeild on the BA website.
8 - Just enjoy yourself :-). BA is a great carrier, and while most posters on the BA board are probably more used to flying further toward the front of the aircraft, there are just as many for whom the "back of the bus" is a perfectly acceptible way to travel.
Regards
Efin