There are no hard rules as to when award seats become available. It depends on project paid travel patterns -- they will avoid releasing seats they think can be sold. So it can be anytime or never.

If seats are not selling above a desired level then seats might be release. This means there will be few seats for peak travel periods to desirable locations then there will be for off time to less desirable locations. The likelihood does increase as it gets closer to flight but some seats if available might not get release until very close to flight time (a week??).

There are other tools for checking avialable (but you need to spend some time learning the tools) but it is always worth a call to see more options than what is visible online. It may cost a booking fee.

As for trading -- this forum does not allow discussions on trading. But always be cautious on trading -- search for threads on points.com in http://www.flyertalk.com/forum/milesbuzz-370/.