About the fireplace/chimney, I'd:
1) Consult with the one local professional you trust most about maybe
doing:
2) Removing chimney, etc. down to hearth,
3) Replacing chimney with metal chimney of size suitable for
4) Woodstove sitting on hearth.

Woodstoves for some years have had to have EPA approval for emissions,
are notably more efficient than in years past, and many/most have doors
with _large_ glass viewing area. Fireplaces are _not_ for heating, but
for ventilating, anyhow.

HTH,
J