I am certain this has been covered but I am overwhelmed with information after being on the forum for a couple of hours now. I'm from the UK doing a TP in January. Most of the advice seems to be about flying and connecting into the US but my question is about going home (ie leaving the US).

I'm flying AA Business class LAX-JFK (overnight arr 7.00am) [into T8]. I then fly later that day (8pm) with BA JFX-LHR (assume T7) again in Business. [I also have BA Silver/OWE status]

I would really like to do a Manhattan run (just because I can, as I have been to NYC a few times. So I have two questions

1. Can I get a shower? Can I get into the FL lounge on arrival (given I have an international same day connection business flight)?
2, What happens to my checked in bags? Will they be checked straight through to LHR ?
Thanks all