Hopefully these will answer some of your questions.
1. The 'Base colour' is the colour that your colour scheme is centred around. I'm not sure what you mean by the Primary colour in this context. If you mean either Red Green Blue (with light), or Blue, Yellow, Red (with paint) then, no. In this context the primary colours are the colours you can mix together to obtain any other colour in your colour space (see question 2). The Base colour defines where your colour scheme is in your colour space. I'm not sure if this answers your question or not...
2. Each slider under the colours in your theme represent, from top to bottom, Red, Green and Blue. On the left there is none of that colour; on the right it is at full intensity. The colours on the sliders show what the colour will look like when you put it at that setting. This is different to many colour selectors you will come across, but it is useful.
3. Each slider is desaturating/saturating each individual colour as you move it as you describe. You're just controlling the amount of that colour in your final colour.
4. The slider directly below the wheel affects the saturation of the final colour, not each individual colour as in question 3. It makes the colour go from near black to full intensity.
I hope this helps.
I am trying to import to photoshop or illustrator ! It is saying invalid format . I just want to import it into photoshop or Ilustrator or even pwerpoint??? HELP