Questions about majors!

Doesn't matter nearly as much as you might think.

Major in what you like. Do well in prereqs. And it might also be worth thinking about majoring in something that might be useful for grad school and/or other careers if you decide you don't want to be a doctor.

 

Medical Laboratory Science is generally vocational. It is meant for those who want to work specifically as a medical laboratory scientist post-graduation. It wouldn't be the best option for someone dead-set on pre-medicine; although, it may be an appealing option if you aren't definitively pre-medical.

The BA vs the BS: First of all, admissions committees do not really care what your major is, so your guiding principle here should be which you would enjoy more, as neither will have an impact on your application. I would go with the BS if you are interested in science as a discipline, i.e. biological basic science research. Put another way, do you want to perform research at some point during your college career? If so, I'd go with the BS. If that's not something that interests you, BA might be the way to go.

 

A BA/BS in any major you can get good grades in.

 

I wouldn't do it.The other options you listed are fine.

Edit: Looking at Purdue's version of MLS, I see an awful lot of medical school-esque courses. There is plenty time to learn that stuff in medical school, and the fact that they would have a yearlong class on serology and another one on urinalysis implies to me that this is a very technical major that focuses on students planning to be involved in ancillary services rather than physicians. Use college to explore other interests.