Is it believable that Clark would seek out Bobby Bigmouth through the Planet?

And I had to look really hard for a really, really sad Elvis song... it's called 'Hard Luck.'

Superman did scour the entire city before he went to the Daily Planet; so he did try on his own. The Daily Planet presented itself as another method of tracking down leads to help find Luthor.

You could feel his sadness as he was looking at Lois's desk items. I hope he discovers she's alive soon. Bobby Bigmouth did give out the clue of cryogenics.

Looking forward to the next part.

Does Perry know yet that Clark has been released from prison? Is that why Clark came to the Daily Planet in his Superman guise, so as not to get into a big can of worms with Perry in his Clark guise?

If I remember correctly, Clark has not been released from prison per se. Henderson is releasing Clark during his midnight to 8am shift to go hunt Luthor down.

Plain Jane is right... I debated whether I needed to jump in and clarify in the story... but I thought it was pretty clear that Perry knew Clark was still in prison. If not, I'll go back in and add another line in this part about Clark's reasoning for showing up as Superman at the Planet.