Yes, your grammar looks fine to me, Ilpoxi, and these days, lyrics don't have to be grammatically correct anyway.
As a native English speaker, the way you have used "the" in #3 is perhaps a little strange: it'd be more normal to say "Where gravity has been caught."
Also, in normal usage, #1 would typically be part of a longer idea, for example:
"I don't know how to save the nation from a war" or "How to save the nation from a war is a problem for politicians today."
"Moving planets form a seesaw" is a great line, btw.
