I forgot to mention the arrival day .. its 22nd Jan and its a Sunday
.. are Hongkong and Bangkok as crowded on Sundays as on weekdays?

Sunday is 'Filippina day' in HK, a hundred thousand or so Filippinas
picknicking in Central/TST/Victoria Park. Other than that there won't
be that much difference.

BKK will be exactly the same as always. Traffic might be a little
lighter though, come to think of it.

Are
some of these attractions closed on Sundays .. Or do these cities have
some special events on Sundays?

Dunno if the royal palace in BKK is open on Sundays. I would think it
is, but I'm not sure. In HK, as I said, Filippina Day of course.

I am more interested in going to Bagkok and want to see "The Grand
Palace" .. read so many good reviews about it. Would it be possible to
see Grand Palace on Sunday in the amount of time I have in the city?

It would be possible, yes, but it might be a little stressing to make
it back to the airport in time. But yes, it would be possible if you
really, really want to do it.

Will I have time left to see anything else?

Probably not,

Does it make more sense to
take a city tour in Bangkok?

In my opinion, given your very limited time and Thai organisation at
times , no.

I understand that its very easy to get around in Hongkong but the
reason I am not very interested in going to Hongkong is because I have
lived in the US for 3 years. And am not sure how different Hongkong is
from the US?
Am I wrong in thinking this way?

I haven't been to the US but I would think it IS very different.

So, if you really want to see BKK, you can, but I still think
time-wise, you'd get a lot more out of a visit to HK. It would be a
lot less stressing too. If you don't get off the beaten track in HK
(like visiting Lantau or something), you can get to the airport within
45 minutes to one hour from wherever you are.

As I said in another post, I dearly love both cities; am merely
advising HK because of time/practical considerations.


Kris