After working for pharmaceutical company for 3 years, I am thinking to change my career-path. I have BS in Biomedical Sciences and I am thinking to go for Graduate School either in MS in Statistics-Biometry Focus or MBA with focus in finance or simply general professional MBA degree.

I just do not want to get back to lab environment when I come back from school. Questions for folks who have been in graduate school or have some sort of similar experience please have your say...

1.) MBA or MS in statistics ? Is MBA really worth it with 3 years of work experience?
2.) MS in statistics- how difficult is grad school? I have taken 3 college level calculus courses and am taking statistics and linear algebra as preparatory courses.
3.) How is the scope of MS degree in Stat? I have heard people with SAS programming can make over 100k is it true? How is the job market? if anyone out there has been to grad school for stat, share your story.
4.) Is it possible to go to full time grad school and work full-time in the meantime. The reason I ask this is my company reimburses for grad school. But I am simply not sure if it is "doable" without over-stressing myself. I would like to hear from those who have done both-full time grad school+ full-time work.

Thanks for your input.