12 day trip in Hokkaido/Tokyo

Hi, i'll be going to Hokkaido in late August 2008. I think i'll need some help with my planning, wonder if u could help me? thanks
1.In Kushiro, we are staying at Masyuko Hostel. What is the best way to explore Lake Masyu and Kussharo? Is it within walking distance?

2.From then, 'll be travelling to Utoro. I'll like to book a room in Shiretoko Pereke near the utoro onsen terminal but there's no email address. If i were to call the number, i'm worried tt they won't understand english.Is there any email address / reservation mtd avaliable ?
I'm considering booking a room in Iruka Hotel,but it seems very far from any bus service. Could u advise ?

3.In furano & Biei, I was wondering in late August, which flowers will be in full bloom n which fields are the best for viewing the flowers then.

4. We'll be staying in furano, then we intend to take the usual JR to takikawa , then catch interesting Ltd Express asahiyama halfway from takikawa to asahikawa instead of from sapporo. Is it possible to purchase a one way ticket ? How many days in advance do i have to book the tics ?

5. After that we'll be heading to Noboribetsu Hot Springs , then Lake Toya on 25/8/08 , 26/8/08 - we'll be staying in Meito no Yado Park Hotel Miyabitei, then toya onsen hotel. Will there be any activities in the hot springs towns at night?

That's all i can think of for now. Thanks in advance !

What is the best way to explore Lake Masyu and Kussharo?

Akan National Park has horrible public transportation. Therefore, a rental car is recommended.

Is it within walking distance?

No. Although, you could theoretically walk it. The two lakes are about 20 kilometers apart from each other.

I'm considering booking a room in Iruka Hotel,but it seems very far from any bus service. Could u advise ?

Like Akan National Park, Shiretoko is badly served by public transportation. If possible, I recommend using a rental car:
http://www.japan-guide.com/e/e2024.html

We'll be staying in furano, then we intend to take the usual JR to takikawa , then catch interesting Ltd Express asahiyama halfway from takikawa to asahikawa instead of from sapporo.

Are you a railway fan? If not, then, I recommend to take the JR Furano Line from Furano via Biei to Asahikawa. It is cheaper and faster. Also, unless you are a railway fan, I don't think that the limited express trains between Sapporo and Asahikawa will be of any major interest to you.

Is it possible to purchase a one way ticket ?

Yes.

How many days in advance do i have to book the tics ?

You can buy it just before departure or up to one month before departure date.