Находится basically means 'is'. I think it's specifically for inanimate objects - i know it's used when taking about where a country is (e.g., Германия находится в Европе, Germany is in Europe).
I think it perhaps implies a bit more permanence than other statements of being...like, yep, that's where the meat is, that's where we've been going for meat since my grandpappy's days
Please note I am also a student so don't take any of this too seriously
Sorry, I don't understand your point. The TTS's pronunciation of «мя́со» sounds pretty natural to me.
In «мя́со» and «мя́са», «о» and «а» are unstressed, so you can't distinguish these forms in speech, only in writing.