Detuning

I'm kind of new at snowboarding, with about 2 seasons of experience,
and I got a new board last year - a Burton Custom X. I can ride some
pretty steep stuff with ease, but often crash and burn when I have to
ride flat, like on cat tracks. This is embarrassing and dangerous.
The scariest place for me is at a local hill where there is a tunnel
that is usually glare ice. If I get the slightest bit sideways in the
tunnel, I'm in for a body slam when I come out.

I noticed that my new board has sharp edges all the way around. Will
detuning the board from the effective edge toward the tip and tail
help this situation? If so, exactly where do you start detuning?

Thanks,
Jack