Is there a way to open/import gschem .sch file in qucs?
The converter now exists:

https://github.com/erichVK5/translate2geda

It substitutes custom gschem symbols *-QUCS.sym that match the QUCS device geometries. You will need to put these symbols in your gschem library search path.

The converter also does LT-Spice .asc -> gschem conversion in a similar manner.

As for "and what does it get you in the end?", it sure beats duplicating a design that's been modelled if one wants to get started on designing a PCB.