I'm skeptical of the idea that it's a normal rocky planet. I mean, it's about 7 earth masses, orbits about 0.02 AU from its primary for a blackbody temperature of about 385K (albedo and greenhouse affect would modify this). And of course it'd be tidelocked.
If it was rocky like Earth and had earth's density, it could have a radius of 12200 km and be 7 earth masses, but then the minimum molecular weight its atmosphere could hold would be about 2.07, just over what's necessary to hold hydrogen, but easily able to hold Helium. So it'd hold all gases in the atmosphere except hydrogen, which would stay for a while but slowly leak away into space. But then, if it could hold onto Helium, its atmosphere could be quite thick - thick enough to lower the bulk density of the planet.
It could have marslike density (3500 kg/m3) and be 14,200 km in radius and have an MMW retention of 2.4, which would be about the same as described above. That might be the sort of density a panthalassic should have, but the atmosphere would have to be rather thick to keep the water liquid at those temperatures.
Or it could have a Ganymede-like density (2000 kg/m3) and be 17,100 km in radius and retain an MMW of 2.9. Again, the same sort of thing as above. This would make it more of a small helium gas giant really.
Either way, we might be looking at a 'helium subgiant' that can hold onto helium but not hydrogen, or some sort of strange tidelocked panthalassic world. That sounds more realistic to me than just 'a big earth'.