Can a Supermassive Black Hole suck an entire galaxy?
No. Even a supermassive black hole with a diameter equil to our solar system is only dangerous up close. Oddly enough, a supermassive black hole has more surface area so the tidal forces are not as strong as a black hole with a few solar masses. Also space is BIG. You would find it hard to fly into a black hole unless you knew exactly where it is.
