You can actually do that with some additional programming:
see:
http://www.youtube.com/watch?v=eMtgK2xanIIyou can do this even with free version.
legality: JCL stated as long as you keep a clearly readable logo and web adress on the startup screen you can do that.
to legally remove the logo and/or startup screen completely you need a PRO version license.(and it is easier to do it natively
)