Question

What problem would be encountered if you tried to dissolve Ag2O with HCl solution?

Answer 1

Precipitate silver chloride from nitric or sulphuric acids we used to pour a solution of table salt in water into the acid until the cloudiness ceased to be produced. At this point, the precipitate was silver chloride.

1)So, I believe that adding the HCl will cause your silver to precipitate as chloride.
2)Since the AgNO3 -> Ag & NO3 ions in solution,
by adding Cl ions, you form the insoluble AgCl, hence precipitation
3)Don't know how you'd go recycling the nitric, as liquid HCl is ~66% water, your solution will get weaker and weaker every precipitation. If you compensate with strong nitric at the start and your nitric concentration is too high you can oxidise the silver -> silver oxide .