> It would be great if I can tap into some of the experience of those that have spent time in Asia.....
Hi! I hope you enjoy Japan. I tried twice to reply with a host of information but on both occasions somehow hit random keys and lost the post, so I shall briefly summarise:
> 1. When is the optimal time to visit? I've heard that March and April are good for exploring weather and cherry blossoms. Any thoughts?
April is best! Check this map to ensure you will see the cherry blossom when you go:
http://gojapan.about.com/cs/cherrybl...kurazensen.htm
> 2. How long do I need in Tokyo. Is it possible to kill a week in Tokyo?
You can easily spend a week there seeing all the different districts (Shinjuku, Asakusa, Shibuya, Harajuku, Ebisu, etc) and if you get bored, there is plenty within reach of the capital. Don't miss Yokohama in the early evening.
> 3. Are there any other 'must see' cities in Japan. Kyoto has been suggested but I think I'll be a little bored with endless temple visits.
If you want to skip Kyoto, go to Kamakura and/or Nikko near Tokyo instead. The Hakone area is accessible by means of a special train from Shinjuku station and offers a beautiful view of Mount Fuji.
Hiroshima is worth a visit to see the A-bomb dome and peace park, as is nearby Miyajima, complete with wild moneys at the top of the mountain and deer near the shore.
As you are entering on a OneWorld flight, you can fly around ridiculously cheaply with the Yokoso Japan fare:
http://www.jal.co.jp/yokosojapan/
You can upgrade to "Class J" at the airport for 1,000 yen even on these cheap tickets but availability is scarce. Note that these fares gave me full JAL mileage credit: I have not tried crediting them to BA but they might yield TPs. JAL do a proper First Class service on some routes that may be worth trying.
> 4. I'd like to stay in the Park Hyatt for those lost in translation views. Has anyone stayed there? Is it worth the room rate? Any other recommendations appreciated.
I have not stayed there but have dined and used the bar there several times. You can enjoy the atmosphere and the view without needing to stay but I am quite sure you would appreciate the rooms if you did. An alternative plan would be to stay in a high-end traditional Ryokan complete with Japanese-style rooms and onsen and be fussed over and served excellent meals, or of course combine the two. Just be careful when considering other Western-style hotels as the rooms are likely to be very small.
> 5. I'm thinking that it would be great to combine Tokyo with a beach holiday. March and April seems to be too early for Okinawa. Anyone have a view on how far I need to travel to find beach sun? Thailand, Philippines perhaps?
I've been to Okinawa in October and November for just two to three nights and both times came back with a sun tan without even spending time on the beach, so April ought to be fine. I recommend the southern-most islands (Ishigaki, Iriomote, etc) but they are very rural and it may be a bit trickier to get by there than on the main island if you do not speak Japanese.
My main advice would be to consider carefully the type of holiday you want to have. You may find travelling light and seeing lots of different places is a better way of experiencing Japan than spending a lot of time in one place but it really depends what you like!