I think you possibly are smarter than me. here are the answers I though of:
1. the Solar system has a total of 17 planets (8 planets and 9 dwarf)
2. the farthest galaxy, GN-z11 with a total of 100 million light years from ours
3. UY Scuti being the biggest known star
4. yeah, I thought the same answer as yours
5. Titan (I'm stupid honestly)
6. I thought it would be safe if mercury was a replacement
7. the TRAPPIST- 1 system. having 7 Exoplanets, with a few being earth-like
I'm not AS smart. I know just some stuff (I honestly never knew Vesta was considered a dwarf planet and i considered Charon as a moon)