2 questions about Strategy tester

 
Hello Dears
First of all, I must say that my English is very poor and I wrote this text with Google Translate. If you see any mistakes in my text, I apologize in advance.
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1:

Suppose I have written a simple (MA cross) expert. In the optimization mode in the strategy tester, when I say optize: (1st MA: from 1 to 300) and also (2nd MA: from 1 to 300).

Now the strategy tester has to re-combine and test all the different modes, right? For example: (MA1 with MA2, MA1 with MA3, MA1 with MA4,......)
In other words, the combination of two 300 becomes 90,000 different modes. But I see that the strategy tester checks much less modes.
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Although this is a simple example of what I had in mind, my question is what exactly I need to do to get the strategy tester to check all modes in the optimization phase.
And if it can't possibly do that, do you have any suggestions?
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2:
Sometimes I write an expert, when I test it in the strategy tester, I see that it is profitable in the last one year or even two years, but it is unprofitable in the last three or four years. Is this considered a weakness or is it normal for an expert? In other words, should the expert I write be profitable in all the past years? How long ago is the criterion?