Right now I think your heat is WAY too high for the copy paper. I always thought that the hotter the better but that is not true at all - I learned that one the hard way . It's the way I learn most things!
For instance, when I foil acrylic the machine is at 155 with copy paper on top. Before ditching the printer (again I have no clue on this printer as most of us a Brother Monochrome or HP), it may well be your foilmaster settings. copy paper is super lightweight so just sandwich with more copy paper and put it in landscape which will reduce the likelihood of wrinkling. I would try maybe 140 and see what happens - just guessing. Maybe someone who had been successful with copy paper can give you a better number. Print some small images and try them at different temps writing down which is which.
Also, I assume you are using a quality foil? That makes a huge difference as well.
Back to the printer - rereading that. First of all, if you want to print on heavier and it won't let you - well that may be your answer there - you will never get what you want on a heavier cardstock. As far as printer settings, you should be able to customize your printer settings. Look for an advanced option when the printer menu opens up - I have mine customized and rename them foiling so I just click on that and get the best coverage. Again, I dont know Samsung, but with most printers you can select your individual DPI and the media you you are printing to.
Some things to try - but again - if it won't print on the heavier cardstock and that is what you ideally want, it may not be the best printer for you. That's a decision only you can make. But in the meantime I would play around and see if you can get good results. Also sure you have chosen the BLACK mode rather than color as even with black under color, you won't get a pure black. Does that make sense??
Holler if this is clear as mud and I will try again!!