Playing card spacing would be a great idea, in my opinion, because you are installing in the low relative humidity months, not summer when the RH is at its highest.

Removed the wood from the boxes, stack in rooms you are going to install, and allow the wood to gain wood moisture content.
If you can get that wood close to 8%, you should have no problems.

Additional expansion space in the field can be a good idea. In the past when necessary we've used thin gauge poly strapping. The problem I see with playing cards....When the planks are fastened the cards will be wedged tight. You'll end up tearing the cards, and leaving chunks in the seams, ultimately defeating your purpose.
Years back we installed 3/4 x 2 1/4 unfinished red oak in a gymnasium , on the CA coast. We inserted pennies in every 5th row, we also left the last 2 rows out. The guys went back 3 weeks later to sand the floor and couldn't find the rows that had pennies inserted. The gap at the last 2 rows was substantially less.

And if it is an exotic species, you better be on the money.

Finished the floor . Used glue and nail, spaced with a piece of flashing (yes, the playing cards would have ripped on me) and it came out great. Now, time will tell come next summer. So far so good, no squeaks. Thank you everyone for all of the good advice, very helpfull. Next year, the other rooms get done!!

That rapid change in RH throughout the year is probably why most New Yorkers use Quarter Sawn and/or Rift hardwood flooring if they've had at least a 5 minute conversation with a professional in the area. And no, talking to a sales guy at Lumber Liquidators, or even an installer from LL, doesn't count as a conversation with a real professional White Oak is still incredibly popular there, not only because it looks great (I admit, I have Rift/Quartered White Oak in my house) but even more so because it's more stable, and why take the risk with plain sawn?

And no, 15LB felt, or any felt for that matter, is not a moisture retarder, it's more to prevent squeaks than anything in my opinion.

Asphalt impregnated felt(roofing felt) does add moisture vapor resistance.
It is not moisture proof, but it will slow down rapid moisture changes like a crawl space on an uncommonly excessive humid day.

I agree with Floorguy