From what you have written, my guess is that your father could have been deported to USSR along with tens of thousands of other Poles to various Stalinst work camps and settlements. He was probably released under the so called 'amnesty' following the German invasion of the Soviet Union in 1941.
He migh then have joined the newly formed Polish Army in Russia, under Gen. W. Anders command and evactuated with the Polish army in 1942. He may then have volunteered for special duty when the Polish section of SOE was being set-up and the cichociemni trainees were recruited. The fact that your father's family had German connections and he could speak fluent German would have been a desirable asset to the SOE.
That he was in Africa, Palestine (now Israel) and Italy might mean he was with 2PolCorps and then recruited into Polish SOE whilst in Italy with Anders forces circa 1944. Polish SOE had trainning bases in Italy and many POlish SOE and cichociemni missions took off from Brisindi, Itlay. I have posted the Polish mission/flight logs earlier in this thread http://warrelics.eu/forum/polish-arm...-3/#post106033 (these came from Kew).