Is it possible to visit those of a higher rank in Jannah? And is visiting the Most Merciful available at all times for all inhabitants of Jannah, or is it restricted to the dwellers of the Highest Firdaws?

Al-Alusi mentioned that the people of Paradise will visit one another, and that Al-Tabarani narrated a weak Hadith about how they will visit one another, stating that the people of 'Illiyyin will visit those below them, but those below them will not visit the people of 'Illiyyin, except for those who loved each other for the sake of Allah. It has been confirmed that the believers will see their Lord in the Hereafter, based on His saying, the Almighty: "Some faces, that Day, will be radiant, looking at their Lord." As for the disbelievers, they will not see Him, based on His saying, the Almighty: "Nay! Verily, from their Lord, that Day, they will be veiled." As for the visit of the people of Paradise to their Lord, Ibn Al-Qayyim mentioned Hadiths about it, the ظاهر (apparent meaning) of which is that all the people of Paradise will visit Him.