1) I have both tickets on one PNR but we're not going to the airport together. I just plain forget, will I be able to check us both in on my phone and then forward one of the boarding passes to her?
Probably, but everyone on the PNR will have to get their documents checked anyways at a check-in desk or the gate before boarding, so you'll probably just pick up paper boarding passes.
2) The OTW flight leaves at 11PM, and we'll have FFD in DFW. Will they let us move around the meal service time-wise?
Moving meal service around onboard? Big maybe... most likely not.
3) The CDG-LHR flight will be European "business" - front of the plane, regular economy seats, middle seat blocked off, right?
Assuming you're flying BA on a narrow-body Club Europe, it should be a blocked middle seat.
4) What lounge(s) would we have access to in LHR during the connection from CDG? We have about 3 hours.
My understanding is that you're flying BA A380 J from LHR-LAS. If so you'll have access to the BA Galleries Lounge in T5 with your J ticket.
5) What will the food be like in BA business class? Is there any pre-ordering? We have our seats selected, 53K/L
No preordering, but meal quality is on par with AA. I personally like the Do&Co catering ex-LHR on BA.
6) Are there any neat amenities on the A380 upper deck available to J pax?
Flying upper deck on
any A380 is still on my bucket list
