Shan, No, not all earthquakes have foreshocks. I'm not sure what percentage have foreshocks. Also, the problem is identifying a smaller quake or quakes as a foreshock(s). I have heard that about 10% (?) of quakes in California are followed by larger quakes. So, if there is a M5 quake near a fault known to be dangerous, it does not mean that you order a prediction and evacuate, because there may only be a 5 or 10% of a larger quake, and the larger quake may be a M 5.5.

So, some people, like me, study fault systems, some study earthquakes after they happen, and some (fewer) government scientists in the USA study short-term prediction (I do not; what I see on this page is more like a hobby). USA scientists have had little or no success at prediction.

You say you have to give the right medicine. I don't think the right medicine exists at this time. But, we should keep working on it. I've said that your efforts might be useful if they educate people to be prepared about earthquakes in areas where they might not be getting accurate information. But, if you are supplying inaccurate information, there is certainly the potential to cause harm. That is why Roger and I and others (Brian) tend to challenge posted statements that we think to be incorrect.

I think your predictions might be a little more accurate if you educated yourself on the geology of fault systems. For example, you might have been more likely to have made your Sumatra predictions in 2005 and recently for south of the equator rather than north.
Chris