galaxies colliding would have such a 'gentle' outcome for us, such as just throwing us off into intergalactic space...

Granted, even as 'dense' in matter galaxies are compared to [what we think it is in] intergalactic space, it is still probably mostly 'space' [similar to the same way atoms are mostly 'space'] BUT i don't see any way it could be anything but a horrifically violent event, especially if the galactic centers got too close to one another [black holes can not only suck up matter, planets and stars but other black holes as well. the resulting release of energy must be titanic].

If you've ever seen a meteor shower, which can be caused by nothing more than our planet passing through some debris scattered in it's path by a comet- i can only imagine what would happen if our solar system passed through a nebulous region [especially if it was star-forming] of another galaxy coming into 'contact' with us [especially since we are near the relative 'outskirts' of our galaxy].

We've actually only traveled a short distance around our own galaxy since 'man' has even been on this planet... we don't even yet know what's in store for us as we make this 'circum-galactic' jouney around our OWN galaxy... much less what will happen if we run into another one!