source code licensing questions

[son goku]

Hi all,
I am a part of a team that is planning to open a start-up company.
We plan to ship a revolutionary storage controller.

We are now investigating possible OS for the product. The choices that we
came up with are either LINUX or Free-BSD.
I am strongly biased toward Free-BSD, however I still need to understand the
licensing impacts of using a Free-BSD kernel.

Browsing the web about the BSD license just made me confused. Seems like to
understand these licensing issues you must be a lawyer.

I got the following questions regarding source license:
1.Do I need to open the source code for my product if I use the BSD kernel
as part of the product?
2.If I do some kernel changes, do I need to open those changes as well?
3.What about Dtrace, if I use DTrace will I need to open code that use it?
4.Suppose the answer for 1-3 is no, s there any other reason why I need to
open the code.

Please understand that my questions stem from the fact that we are afraid of
exposing our source code, especially during the first phases of the project.
It is more than possible, that we will re-consider our approach in later
stages and open some or all our code to the community.

Thanks!!