I am not sure what you are asking exactly. Your first question doesn't seem to relate to your second question. Could you clarify?

The term "Arbeit macht frei" didn't refer to physical freedom, as in being let go, it referred to spiritual freedom gained through work. It seems to have been used in the camps to state that working for the state through labour brought some sort of spiritual freedom, not actual freedom.

Not that prisoners saw the expression as meaning that. They tended to think it made a mockery of their situation.

I'll tackle the second question first: yes, some Polish Jews were able to avoid the death camps but only temporarily and up to a point. Bribing a German or collaborating with the Germans through membership in a Judenrat (Jewish Council) could defer transportation to a death camp but it could never buy freedom. There was no freedom for Jews in Poland, every Jew was subject to the anti-Jewish regulations such as wearing the star, living in restricted areas, working for the Germans, etc. The best a Jew could hope for was being allowed to keep on working for the Germans rather than being sent to a death camp. I am not aware of any Polish Jews having been able to bribe their way out of the country to freedom. In other countries than Poland (which suffered the worst fate in terms of Jewish dead) there was more scope for bribery. A famous example is the Kastner train, which left Budapest for Switzerland in the summer of 1944 with 1600 Jews on board who had paid (or been paid for) their escape from the deportations that were then in full swing in German occupied Hungary.

As to your first question: please see here for the crucial difference between a concentration camp and a death camp. From a death camp there was no release. Were Jews ever released from concentration camps? Before the war, Jews could be and most often were released from concentration camps (unless they were there as political prisoners) as the pre-war goal was to drive the Jews out of Germany rather than keep them incarcerated indefinitely or kill them. There were two large waves of Jews being sent to concentration camps before the war: in early 1933 after the Reichstag (parliament) fire set by a Dutch communist prompted the establishment of the first camps; and in 1939 after Reichskristallnacht. Both times all of them (except for the thousands that died) were released after at most a couple of months. At this time and as far as the Jews were concerned the camps were used as a terror tactic to force emigration.

Once the war was on and particularly after 1941 when the end goal had changed to extermination, release from concentration camps became well-nigh impossible for Jews (though it remained possible for other prisoners). Only by the end of the war did Himmler start negotiating with some countries for the release of some of their concentration camp inmates in a bid to win their goodwill and save his neck. Thus happened the release of 400+ Danish Jews from the ghetto of Theresienstadt in April 1945.