That's actually a myth about ice sharpening the blades Sim so perhaps you need to invest in new blades. I would certainly contact your consultant re the handle becoming loose, it could result in a nasty accident if it happened to come off completely whilst the bowl was full.
I wonder if you took the blades to a knife sharpening place whether they could actually sharpen them, no-one has ever said they've done this but you could at least ask the question. It may not be something Vorwerk would recommend though.