No, hodgman is correct.
d.)Render target texture color = ARGB(1, 1, 1, 1) (than i render this texture it has all pixels alpha == 1)
This is wrong. Your target has an alpha channel, and therefore will write to the alpha component. Which in this case will be .3.
If you want to do that properly, createa a render texture as RGB, not ARGB.