Oh, almost nothing gets pulverized when galaxies collide! Our Milky Way galaxy is currently colliding with a couple of small satellite galaxies. There's so much empty space between stars that almost none of the stars themselves impact.
It's more a matter of the gravitational orbits of the stars inside the galaxies changing dramatically. But those changes caused by a galaxy merger take millions of years. Plenty of time for life to adapt.
The biggest danger to life would be the possibility of getting blasted by radiation, if you ended up too close to a supernova or something like that.