The universities that you have listed are great for premed if you ignore costs.
UMD is also great for premed. You are in-state.
Medical school is really, really expensive.
I will admit that my experience in this area mostly comes from what I have read on CC, plus having a daughter who is starting a DVM program in late August (really soon now). DVM admissions is not identical to medical school admissions, but it is similar and there is a LOT of overlap in the premed / prevet requirements. Because of this my daughter knows quite a few premed students who she met in her classes.
My daughter attended a university that is barely NOT in the top 100 in the US, but that has very good premed and animal science programs. She found that premed classes were full of VERY strong students. She found great professors. She did really well in DVM admissions and will be attending a “top 5 in the world” program.
You do not need to attend a “top 50” university to do well in medical school admissions. You do need to do very well in very tough classes. You need to get quite a bit of relevant experience in medical situations. You need to avoid debt if you can.
To me this implies that undergraduate admissions for a premed student should be boring. There is something to be said for coming in near the top of the class at an affordable in-state university when your goal is to graduate near the top of the class from an affordable university.
UMD is a great school and should be affordable for you. WUSTL is a great school and would be great if it is affordable. Your being legacy is likely to help with admissions when combined with your strong GPA.
If I were you I would run the NPCs, and drop everything that would leave you with any debt. Also, given that you have both a dad and a step-dad, I am going to guess that your parents might be divorced and therefore you should be aware that the NPC might not be accurate. Reality might be worse than the NPC predictions.