Thanks for the clarificaitons and suggestions. I've incorporated some and will incorporate some more a little later today.
On the blankets and pillows --- these are so hit-or miss-- I do occasionally see them on the Shuttle, and I frequently do not see them on other short Mainline flights, so we can just leave that one as YMMV.
Also leaving in the bit about the RCC's; I know a few folks who don't mind a hike and a second trip through Security if the reward is free liquor drinks
Financially, Amtrak is often a cheaper option than flying between DC and NY, but I consistently have issues on Amtrak. Especially in the summer, when trains have to keep lower speeds and break down more often due to the heat. I've had the 3.5 hour journey sometimes take 7 hours on the train; at least US has another plane leaving in an hour so if this one breaks, you get on the next one. If the planes flew to Penn Station and Amtrak went to LGA I'd never, ever take Amtrak; usually if I need to go to NYC, I book a refundable Amtrak ticket in advance, and wait to see if the airfares come down. You can actually get some good deals between DCA and LGA especially on the weekends, if you wait till the weekly e-savers come out.
Amtrak DC-Boston would just be brutal.