Aleksandra, I have F3HP bodies and also have that same E series 28mm lens.

It is a good lens, not brilliant, but good.

With regard to checking out exposure and/or scratching, I myself always run a roll of slide film through a camera and lens combination.

The actual slide is the actual film through your camera, so any results are not altered by any later process.

I then use a light box and inspect the individual slides under a magnifying glass. Any defects caused by the camera, as in scratches, will show up straight away.

Assuming you don't have a light box, simply tape your film to a window that is not in direct sunlight, then view them though a magnifying glass.

Clean the glass first though, otherwise your film will end up full of dust

Mick.