Am already 1 or 2 on google.com but how can i make it 1 or 2 on other google like google ca google au and more.
usually this requires your site being targetted at those areas. In Google websmaster tools there is an option your you to set the geographic region for your site. Also try gaining backlinks from other webstites and blogs in those areas
It will definately effect your US traffic. You can choose not to target it and Google will determine where it comes up the best depending on your target and link pointing to your site.
you have to create some sub sites for those geographical locations, and somehow connect to the main website. as said you cant be king everywhere
Um am not sure what you mean with the sub forum. i can build arcade but i don't know how to target those location
I think the source countries of backlinks would decide how well your sites rank in those countries. So, get more backlinks from your target countries. And, using the local keyword in your niche would help your SERP, too.
You can also get links from sites that end in the domain you're targetting (eg: if you're targetting australia then get links from domains with the .com.au TLD), - That will help.
Backlinks from the sites with specific TLD and hosted on the targeted area will help you to rise your Google ranking on the TLD you want.