Really appreciate your comments. Would comment as follows
By the way not staying at Shinjuku Washington but at Citadines Shinjuku 3 nights 25th May to28th May and then again 3 nights from 6th June to 9th June - that was old itinerary
Itinerary didn't print out right only arrive in Tokyo 9 am the Friday 25th May so only have 3 nights there initially, but plan now to go to Nikko on the Sunday 27th May before leaving for Hiroshima the following day
Yes agree that need more time in Kyoto, so planning to just spend one night in Hiroshima prefecture an will go to Miyijima as a day trip and leave to go to Kyoto on 29th May rather than 30th May. Will also visit Nara as a day trip as suggested.
When you say spending more time in Koyasan what would that be instead of? In what way would those days be tough if we do as I Said in 2. and make Nara a day trip during a 4 night stay in Kyoto. Are these days going to be tough because of too much travelling - should we cut down maybe time in Takayama if you favour Koyasan?
Already touched on this one and will do Kamakura on one of the days when we return to Tokyo, i.e.between wednesday 6th June and saturday 9th June when we fly home.
Sounds great - nice idea to visit Nikko at the start, and you can always give it a miss if you're too caught up in the city :). I also think the adjustment to the Hiroshima trip sounds good. By the way, other travellers have really recommended staying on Miyajima island rather than in Hiroshima - you may want to consider it if you're only there for a day. (you can also store your luggage at Hiroshima station and take a small overnight bag with you to Miyajima - highly recommended).
About Koyasan, I think the about of travelling time will be quite intense over this 2 day period, especially as you'll also be doing a fair amount of walking at Koyasan. Here are some sample itineraries from Kyoto to Koyasan(2h40m), and from Koyasan to Takayama(6h20m) showing a total of 9hrs on trains for 2 days.
That being said, I don't know what I would substitute out of your itinerary to give you more time... Perhaps you could aim to leave for Koyasan first thing in the morning, and then aim to leave Koyasan for Takayama after midday to give you the most time in between trains? I think the 2 nights in Takayama will be well spent, especially if you arrive there later in the day.