Re: So Bajor made one of it's moons uninhabitable for some energy
With star trek tech, it doesn't make much sense - starfleet could have given the bajorans a few fusion reactors, for example.
Within the confines of the episode - either ~half a million people starving/freezing/dying or destroying the ecosystem of an uninhabited moon - the second option wins.
Yes they could have, perhaps the Federation offered but were turned down. Or perhaps it was a pride thing the Bajoran's. They wanted to stand on their own two feet and do it by themselves.
On the continent of wild endeavour in the mountains of solace and solitude there stood the citadel of the time lords, the oldest and most mighty race in the universe looking down on the galaxies below sworn never to interfere only to watch.