Why are we not so worried about blue shifted...

[jd2pink]

...stars and galaxies?

[shadowise]

Mostly because they are the exception rather then the rule. Most of the galaxies are going away from each other at an ever increasing rate, leading to a dark and cold Universe in the very distant future (unless this trend is reversed by some unknown physical phenomenon). Only within a local group of galaxies can you find some that are approaching each other. For example, Andromeda, the closest galaxy to our Milky Way, is getting closer to us, so the light coming from it is marked by a blue shift.

[My Icon is a Blimp]

Blue shifting galaxies are ones that are headed more towards us than away. The spectrum we see from a galaxy is a combination of its more or less random speed relative to us due to interations with other galaxies, and the redshift from the expansion of the universe.

Unless a galaxy is very close, the redshift expansion will dominate so that only redshifts are detected.

The big exception is the Andromeda galaxy, which is a spiral just like the Milky Way galaxy, and a "mere" 2.9 million light years away and is the closest big galaxy to ours.

In terms of being worried about it well...Andromeda is heading out way, and well collide with the Milky Way Galaxy in about 4 billion years or so.

That means is one were to stand on Earth or Mars the sky would be increasingly taken up by the fuzzy blog of Andromeda until suddenly (relativity speaking) the whole things is a huge explosion of stars.

Not a literal explosions. Stars are very far apart from each other relative to their size, and about zero stars will actually collide.