Hito is not a suffix. It is 仁, meaning benevolence. Hiro, 裕, has the meaning abundant, hence abundant benevolence. Akihito has the same hito, but aki is 明, meaning clear or pure. Note 明 can have other meanings, but with other readings. Thus you are likely to see Hito in many names, as it's just a positive characteristic, but not otherwise a suffix relating to royalty or anything like that.

Akihito does have a second name, but for future use. The reason Akihito only has the one name now is that he's still alive. Emperors have posthumous names used after they have passed. Hirohito isn't generally referred to as Hirohito in Japan, but as Shōwa 昭和, hence the reason we refer to his reign period as the Shōwa period. Emperors in Japan have a different name by which they are referred after death. After Akihito passes, he too will have another name that will be what most people use. That's why you have two names on most of these. Akihito will be known as Heisei 平成 to future generations, the name of the current period, just as Hirohito's Shōwa period was the source of his posthumous name.