In no way was it a guaranteed eventuality that China would attack Japan to get Manchuria back.
Whilst I would agree with the previous poster that the condition of China's economy and industrial base is slightly better than what's been alluded to they (the Chinese) were still in no position to field an army of the same skill and quality of arms as the IJA.
I think that it should also be pointed out that Japan didn't need to invade China for the foodstuffs - there was regular and robust trade between Japan and China in the pre-war years of '34 - '36. If no conflict occurs in '37 why should/would this change?
So let's follow the TL as suggested by the original poster:
Japan does not attack China in '37. Japan isn't stupid - an attack on the USA or the USSR whilst being dreamed of is not going to become a reality any time soon. However, aiming at the old colonial powers would be fair game and I would suggest wouldn't necessarily guarantee war with the USA.
China was a major tungsten trading partner of the USA both pre and during the war. The war between China and Japan upset this (especially considering that even during the war China kept trading with Japan when the Japanese outbid the US!!!) and helped lead to sanctions which led to war.
So, no war with China. A fully intact IJA and the IJN to transport it and screen it. Southeast Asia and the South Pacific doesn't stand a chance - I think that there is a very real possibility of Indochina, Singapore, Malaysia, Dutch East Indies all falling to Japan before the USA awakens to the very real threat to Guam, Phillipines and it's other interest in the Pacific.
My questions are as such:
1) Could we see a bold and brash landing in Northern Australia before the USA forcefully reacts?
2) Would a delayed or even non-occuring Pearl Harbour lead to a change in US Naval tactics - aka the belief in the Aircraft carrier (or had that already happened?)
3) Does an alliance with Germany still bring Japan and the USA/USSR into conflict with it? Does Japan still completely ally with Germany considering Germany was still arming and training the Nationalist up until the '37 war?
4) With no war in China, thus no guaranteed sanctions by the USA thus no specific 'casus belli' for Pearl Harbour when exactly does the USA and Japan come in conflict?
5) What does the Sino-Japan picture look like at the end of the conflict?
Some of my resources:
http://www.mnstarfire.com/ww2/history/campaigns/China.html
http://www.iisg.nl/hpw/papers/debinma.pdf
Thanks for reading - Blitz