Is it ok to alert Human Resources about concerns that caused you to resign ? ?

This is just my opinion and many may disagree; I'm not sure there is an absolutely right or wrong answer. You have only "invested" less than 90-days of your life with this company and it is good to find out now rather than several years down the road that you and this company are a bad fit. I would simply find another job and then resign. The other option is not worth the stress. I lost a job in 2002 that probably could have resulted in a lawsuit against the company and I considered it. But the truth is, I didn't want to wake up angry every morning for the next 5-years, which is what would have happened if I had sued them. My life and peace of mind is worth more than any money I might have acquired through the law suit. And don't forget, you might file a suit, live with this for another 5-years, and still lose the suit. My advice: move on with your life and write this off as a learning experience.