Regarding one point:
i definitely couldn't make vector art properly(I have Inkscape and i often make Vector art just fine.),
You are comparing two different types of software here. There is software for vector art (like Inkscape, Flash or Illustrator) and software for pixel art (like paint, Photoshop or Gimp). While today most of them can deal with the opposite a little bit they all have their special focus. Usually doing the opposite with them is no fun at all, because they are bad at it.
So if you plan to draw and work with vector images I highly recommend one of the programms which were made for this. But if you want to edit pixel files (like photos) and use typical methods for this a picture editing software like Photoshop or Gimp is the better choice. That's why designers usually have installed both - one tool for vector art and one for pixel art.