JR East Pass and Matsumoto

I am a little confused about the JR East pass. Are all JR train travels in the green area marked as JR East Free Area covered? Or just those on the JR East lines?

For example, I am looking at the Ltd. Exp. Shinano 1 from Matsumoto to Nagano, I believe this line is operated by JR central. Will be pass be valid? If not, how can I look up just the JR east trains between those destinations? Thanks.

The JR east pass covers the shaded area. I asked about this specifically at a station last year--the pass will cover travel on the Limited express Shinano up to Shiojiri station, even though the train runs as JR central.

On the train, I showed the attendants my pass and told them I was stopping at Matsumoto and it was all fine.

Can someone confirm that we can travel Aizu wakamatsu to Matsumoto on a JREast pass?

I am glad to know that I am not the only one with such a question.

I took the JR Banetsu sai line from Aizu Wakamatsu to Koriyama shinkansen station on the way to Matsumoto.

From Koriyama, you should take the bullet train to Omiya, transfer to the Nagano shinkansen, Asuma and then take a JR Shinonoi local or Limited Express Shinano to Matsumoto.

All of this is covered by the JR east pass.

I notice that the JR East Pass 3 day is Y10000 in Japan, but the quoted price to buy in Australia is more than the equivalent comes to.
Is it better to wait and buy it in Japan?

There is a limit of one pass per person if you purchase the pass inside Japan. If you purchase outside of Japan, there is no limit.

If the price difference is large and you do not mind the limit of one pass per person, I guess it would make sense to buy it in Japan, instead.