Best sharpening option in G6?

What option should I choose to get the best quality in the sharpenings settings?

I have heard that is better performing the sharpening in Photoshop. The G6 has two otions for no sharpening: Low sharpening and Minus Sharpening. The question is: which one is better? I suppose that both options don't degrade the quality filtering the image so it looks soft, isn't it?

So it's necessary to sharp, which is the best sharp filter for the G6?

Anothe question, why the photos at f 8 are less sharp that at f 5.4? Should I avoid higher f?

Thanks in advance and sorry for my poor enghish.

I'm not a pro, nor a look for absolute perection which in iteself may place us in an infinite path..... Sharpening, I would say low is the best (from what I have seen and experienced) and the focus issue...think of it like this...(the smaller the f, the "more of the picture comes into focus" at the expense of any specific area (specially in the forefront) . Also, the smaller the focus the greater of depth field....

Regards, and above all.....enjoy photography....

Alex