Epic Yuri.
You're going to discover all the powers are "abusable". To manage a
campaign I suggest offering the players motivation via council
enforcers (angels/agents), highly equipped mercenaries/militia or
xelomites.
Players can annhilate civilizations, but why, and for how long will
they enjoy pursuing such activities? Try and help build character
connections to mortal non player characters, as this is where some of
our best adventures spawned from. My brother's character attempted to
fire an AI (in a hardened masterly crafted android body) he had
running his porn empire by throwing him out of a 70 story window into
traffic. When the AI and android frame survived the impact and
returned to the office to discover why he had been relieved of duty,
my brother's character made a campaign long ally. He went out of his
way to help and protect the AI whenever possible. AIs can be much more
durable than human (or many alien) npcs.