ummm okay here goes....
Ghost Rider's powers are mystical in origin, (it comes with the territory of being a demon). This has been more or less shown in his appearances with the likes of warlock and strange.
As I stated before the stare can reflect back to the staree all of the physical pain, emotional greif, and psychological damage that the staree has commited on others.
Cain Marko's childhood fears won't effect him because that's not what the stare relfects back to the person.
In physical combat GR is certainly no slouch either. He has probably slightly more physical strength than spidey and while his reflexes and agility are not at spiderman's level, his overall fighting speed is way above peak human levels.
(In one showing a demonic hobgoblin raced all out towards GR at full speed, GR simply stood there and took it, hitting the glider turning it into a pile of shrapnel and knocking hobgoblin back aways.
While Juggs has enormous physical strength, he won't win by physical means, he can only subdue GR for short periods of time sine GR takes only a few moments to reform from dismemeberment.
GR has a weakness to hellfire from other demons like vengeance and zarathos, but since Marko possessess none and is not a demon he has no way to put GR down physically, nor does GR him.....so in the end it will come down to the penance stare. After seeing GR nearly back down Galactus with it, I have no doubts he can do so easily to marko.