You are not adverting sufficiently to the significance of the two little words at the end of your hypothetical but very real example: "for free".
If someone with a computer doesn't know they buy software at a computer shop (bricks 'n mortar or online), then their ignorance is willful and therefore culpable, ie they are chosing to ignore the moral issue for the sake of money. That is itself immoral.
No. This was addressed by my first point (which you conveniently left out). They want it for free because the price of Photoshop is completely unreasonable. If Photoshop was sold at a more reasonable price more people would happily buy it.
This second point was to address your statement that more people would use FOSS if it were a financial decision. I'm saying the reason most people don't use FOSS is because they don't even know that it exists because let's face it FOSS is geek domain so you can hardly call their ignorance willfull.