Why is this a Gas Giant?Your planet has 0.0% hydrogen and helium, combined with a mass of 3751.0x Earth, which exceeds the gas giant threshold.
Gas giants form when massive cores capture enormous atmospheres of light gases. They typically form beyond the 'frost line' where volatiles can condense.
Outside the synchronous orbit: slowly receding, like Luna (~cm per year).
Tidal braking locked the planet to its moon: one face forever moonward.
Tidal heat sustains a subsurface ocean over a rock seafloor: a strong candidate for life (Europa-like, 100/100).
+5 temperature: large moon stabilizes the axial tilt - steady seasons+10 geology: tidal flexing sustains geologic activity+5 magneticField: a large close moon may help stir the core dynamo (speculative)