Originally Posted by
Udaman55
if we check bags will ba let us check bags all the way through such that we can stay airside?
You can't plan on it, unfortunately, because the policy is NOT to check them through on separate bookings.
if we don’t check bags can we stay airside to avoid immigration, any reason why I wouldn’t be able to get my London to Paris ticket printed in Austin before departure?
They will probably not be able to print your London to Paris boarding passes at Austin but the flight connections counter at Heathrow will be able to do it, enabling you to stay airside.
if I have to go through immigration are there any perks for being in first class?
If you are a non-EU passport holder, you can use the Fast Track, however, it's sometimes slower than normal non-EU immigration queue if there are only one or two desks working on the non-EU Fast Track lines if there are people with issues. You can see both of the lines so you can assess it when you get to the immigration area.
If you are a EU passport holder, then there is no perk for flying F, but you should be able to use the automated machine.
If you flight arrives before 1 pm, you could go to the arrivals lounge landside (after immigration and baggage hall) if you need to collect your luggage. Arrivals Lounge closes at 2 pm so there isn't much point in going to the Arrivals Lounge if your flight lands after 1 pm.
Your post suggests that you have award tickets. If it is a one-way ticket, then you can just cancel the LHR-CDG sector and save the Avios. However, if you have a return ticket, you need to make sure that any sector(s) that you do not intend are properly cancelled and tickets re-adjusted to make sure that only the sectors you will be flying are on the ticket, because if you fail to fly a sector part-way through your travel, subsequent sectors on the same ticket will be cancelled (this generally apples to both award and cash tickets but being on award ticket actually makes life somewhat easier as you do not end up having to have everything re-priced and potentially pay a lot more).