No problem on your 2nd language of English, I got the basics of what you were asking. ?
I'm not aware of any extension pieces you would need to buy with FX 5/6, I never needed to replace any parts when I was running mine.
You can't really over filter (over pumping) your tank but there could be too much water movement for some fish. That is easy to fix by directing the output flow from the filter by adjusting the nozzles or position in the aquarium.
I have never heard of female frontosa having fry (babies) on their own without a male in the tank. They will however produce eggs but they won't hatch. More than likely there was a male frontosa in the tank that wasn't identified as one.
Is the only thing wrong with your Eheim filter that the manual push to prime button on the top doesn't work? If so, you may still be able to use it by manually priming the filter by putting the filter back where it normally sets, opening any valves for the filter and then sucking on the output end of the hose. It should naturally fill with water and once the water reaches the rim of the aquarium and you can reinstall the spray bar or nozzle and then plug the mains cord back into the wall outlet.
If you post the actual model number of your filter, I might be able to help you further.