Yes, the German/European version only has Phono-in and a DIN input but I don't know if the DIN input works like the cinch line input of the American version.
The M70 is worth the wait, it's loud, sound very good, looks classic, is built well and great in portability (handle and strap). A member here sells replica straps which I would definitely recommend

The M70 will also last veery long on batteries even though it puts out some strong sound. All in all the M70 has little to no weak points.
About the taxes / custom duty. Yes, you will probably have to pay some. You'll have to pay 19% vat (MwSt) on anything above 100€ and probably another 10 or something percent customs. It's hard to find any clear information on the internet as the whole custom duty system is pretty confusing

If you're lucky you might be able to convince the customs guy that the boombox you got is old, worthless and was a present from someone you know over there. Then you won't have to pay anything.