Hello,
While the Manei Domini have gone out of their way to strip themselves of much of their humanity--both figuratively and literally--they do still concern themselves with eating, sleeping, and hygiene as normal humans do. After all, their necessary organic parts still require sustenance, and their cybernetics require recharging and periodic maintenance to stay in top form.
As to personal entertainment, the Manei Domini mindset is much like that of a monk. They remain aloof from non-Manei Domini most of this time, engage in training exercises, and partake in any number of rituals and studies designed to reinforce their devotion to the Master and his cause. For some, these rites may even be part of a process aimed at maintaining the efficiency of their neurological connections to the cyberware they've opted for, since BattleTech wetware-to-bionics interfaces can be somewhat crude.
Beyond that, what little free time a Manei Domini has between exercises, maintenance, "prayer", and duties is likely spent on hobbies. Some may listen to music or watch the latest vids from Solaris VII. Others may paint, draw, or keep a journal. Apollyon himself is known to draw some comfort from studying natural landscapes.
Hopefully, that helps you.
Thank you,
- Herbert Beas
BattleTech
Catalyst Game Labs