Do you think you can make it as a performance major? Obtain an orchestra chair (that will pay enough to live on)? Most performers teach throughout their music career, either at local music schools/shops on a contract basis, develop a private studio or base of students, or a combination of both.
For most performing musicians, income is the sum of a couple of lower paying orchestra chairs, private teaching, small gigs and local venues, and maybe even a day job.
A music ed degree will give you the background, theories (musical as well as educational and psychological), student teaching experience, and a step towards (if not downright) state initial teaching certification/licensure within your state. Depending upon the public district/system, some will hire a BM performance grad if there's a shortage of qualified mus ed grads, and help you through the certification/licensing steps. Employability, as does pay scale, varies widely across and within states.
Most states will require you to obtain a Masters after x number of years.
There are schools offering dual majors in performance/ed, but I don't think BU is one; I may well be wrong. There are also some 5 and 6 year programs, culminating in an MM or MMusEd, combining the performance music ed disciplines.
There are also Masters programs in performance/pedagogy, where the teaching methodologies are geared to individualized/studio instruction as opposed to a group or classroom approach. Specific programs, like Suzuki specialization are also offered, at both the grad and undergrad levels.
ASTA
ASTA | HomePage and MENC
Information on Music Education. Information on a wide variety of music education topics of interest to teachers, parents, students, researchers, music industry professionals, and others. are great sources of info as is this Rice link
Navigating Music Careers
These are general answers. My son was a 5 year BM viola perf/mus ed major for 5 years, dropped the ed part very short of completion (student teaching and a couple of credits short) and graduated Hartt with a BM in performance and a very heavy music ed minor to pursue performance in grad school.
Think about specific questions, and ask away.