I went 2 times in Japan. First time was to offer my wife a trip for her 30th anniversary.
Second time alone in Tokyo : Half work, half vacation.
So first time was a trip during 3 weeks.
We took a 2 weeks JR pass because we plan to move during 2 weeks and keep 1 week for Tokyo.
Here is a quick overview of what we visited :
- Arriving in Tokyo and stay 3 days to plan and visit a bit.
- Going to Nikko (Toshogu Sanctuary) : an astonishing Temples complex in the gate of a Nationnal mountain park
We spent 2 Night, visited the Sanctuary, have a long walk in north area... Peacefull and amazign.
- Then we were going to Nagoya to reach Takayama : center of this city is traditional and looks like some
sets in Kurosawa movies. It's better going to this city during the Takayama Matsuri :
www.japan-guide.com/e/e5909.html.
- Kyoto was the next step (JR pass is useless in this city) : lot's of temple, nice walks and good restaurants. Stressless than Tokyo.
- Hiroshima.
- Himeji Sacred Island.
- Going back to Est :
- Himmeji city and his big castle.
- Nara city to visit Nara Koen (parc) and the Giant Buddha (wow).
- Spending time again in Kyoto.
- Back in Tokyo : I killed every toy stores ^__^
So my advice :
1)Accomodation: where would be the best place to rent? About how much?
For a first trip, I recommand to move to different cities. Visit country side, it's beautifull and people are more "friendly" in communication.
2)Location: Is there anywhere central that we can go that will be accessible to almost everywhere?
For a quick trip, you can stay in Tokyo or another big city and use it as a base for travelling (Shikansen train is fast).
3)Transportation: Would getting a train pass be worth it?
Yes if you are moving from city to another or moving form tokyo to other area (see above).
Method 1 :
It's better booking train reservation for an "end of afternoon" travel.
So you arrived at your destination, put your lugages at the hotel, go for a diner in a restaurant, then sleep or party ;D
Then in the Tomorrow morning, you are fresh to discover the place (Sikansen is fast, but smash you a little bit).
-> the best is to book 2 different cities for arrival and departure : your travel from city to city will be easier (straight line).
Method 2 (ref to 2) :
You stay in the same hotel in the city-base of your choice, each morning you take the train to reach the place targeted,
the coming back in the evening.
About JR pass : you buy it in your country, and activate it in any central train station.
JR pass is about duration, not from monday to sunday.
You don't nedd a pass if you plan to stay only in Tokyo. Use Metro or by a simple bike, it's less expensive, and more fun.
4)Language barrier: is it a big issue?
Nani desu ka ? Ha ha ha... it depends... Then are quite average good in english in big cities... but country it's a lottery !
5)Guide: do we really need one?
I took the lonely planet guide : very good guide.
6) Lenght of stay: what would be a reasonable lenght?
Depends on your money... 2 weeks is okay, but 3 are better.
About toys shopping, Tokyo is the focus. Mandarake (Nakano and Akiba) is very good, but sometimes,
do not hesitate to visit toys floor at Yodobashi Camera : when a new toys is out, they offer discount price,
very discount prices.
Food is cheap : depends on your budget, but keep restaurant for dinner, good to have some rest after long walks.
Toyoko Inn is a very good hotel company, in every big and average cities.
So many things to say.
Feel free to ask