Hello, I'll leave for you some possible suggestions.
I hope this will be of some help.
in the 2nd stanza,
でもこれだけは信じてほしい
It definitely means 私はあなたにこれを信じてもらいたい([but] I want you to believe in this), in which てほしい implies that the speaker wants someone to do something.
Marked for footnote 1,
なぜかしら何か起きるというの
Literally translates to "is it that something's gonna happen [in the near future]?", noting that we might often use present verbs for describing the future event with no specific markers.
Source: http://mysound.jp/song/5212869/