Smithsonian Castle

Less than an hour for sure

Nobody should be sleep

Most of it is blocked off, similar to other large building tours.

Yes, it is the only Castle on Smithsonian grounds and the original building around which the current Smithsonian was founded. It now serves as the welcome center.

There are a few of the original exhibits that have been there a very long time. I found the architecture to be the most interesting thing about the castle.

Parking right next to the building and ramp entrance

I would do a Google search.

No. They sell them inside

Free

Yes, there is absolutely a cafe there. I know because I had a corn muffin and an energy drink there. I quickly regretted my selections but muffins cannot be returned once you've taken a chomp...

There isn't a whole lot. There are some spots on Jefferson St. But there aren't many. Your best bet is really to use Meyro.

Yes

No timed ticket required

Smithsonian museums are FREE

Pets are not allowed at the Smithsonian museums, but they are welcomed at the outdoor gardens.

9 am and 1 pm

All the info is in the web page

Virtually all attractions are open at the Smithsonian complex. In several museums there are areas under maintenance, most will be open in the spring of 2019, probably in the second half of March.

Yes, surely

If you tell screeners, they can wand you or possibly do a pat-down. You should have received a wallet-sized card when pacemaker was implanted. Bring card when you visit. PS..not all of the 19 Smithsonian museums have metal detectors. I'm almost positive The Castle doesn't have them.

Yes