Whenever possible I’ll always do Pearl Heavy, even ultra heavy. :-D
Assuming my sub is alive (wasn’t attacked or it submerged), I’ll go sub, dd, 3 ftrs, ac, bb, bom. I’ll clear in one shot and if the US happens to get 3 hits, I’ll lose the ftr instead of the DD, leaving me with 1 dd, 1 ac, 2 ftrs, 1 bb. I can’t see the US hitting that and they are more than welcome to try.
I actually have no problem buying an AC (or DD) on J1 if I really need to. It depends on the Allied units and where they have their planes (or the UK sub) but I’ve found a third AC pretty helpful in games where I chose to buy one.
I think anytime you can use a BB to take one of your opponents hits you should try and find a way to make it work, and having that BB take either the AC or Ftr hit means you can probably get out of there with just losing the sub.
If I did go Pearl Lite I’d use as many planes as possible and probably the DD. So what is that 4 ftrs, 1 bom, 1 dd? I think 4 ftrs can reach. If not then 1 dd, 3 ftrs, 1 bom or something along those lines (and sub if it is alive) or if I really need another ftr elsewhere.