Always better to have it on and make a quick rescue than have to take that extra second to change one's clothes. And does Lois undress Clark at any time?
Well, my first thought was "he was lucky he was not wearing it while on the stake-out with her in "The Phoenix"".
My second thought is, she does not have to undress him. His clothes could get really wet, or torn, or damaged in some other way.
He has to stick that engagement ring somewhere in WHaLtTA
Does he pull it out when they are in the clouds?
No. Freaks make sure that when rushing off to a rescue that their hair looks neat and tidy first.
Pre-amnesia alt-Clark:Well, if you lost all your privacy because your disguise was exposed, you would go to extreme lengths to protect it to.
Superman falling will cause confusion for Lois.
Only if she notices this. Plus, he jumped not fell.
True, although it was not a graceful flying down.
Well, he could try to distract Lois from his inability to fly.
Um... wouldn't she want him to fly off and stop Nightfall?
Not if he kisses her. Although would she let him kiss her, being she is in a relationship with Clark. OK, so maybe that would work. Tell her he is trying to find clues on who kidnapped Clark. OK, I guess you have a point.
He could just tell her the truth.
SUPERMAN: Hey, guess what? I'm really Clark. <<spins into CK clothes>>
LOIS: So, you have your memories back.
CLARK: Um... no. Cat told me.
LOIS: *CAT* knows? And you haven't told me?

of him.
Well, as I said, I thought it was a bad plan.
Still being outside without shoes is a bit strange when one lives in the city and alleys are usually full of broken glass.
Hmm, the last point is a very good one.
I always wonder how much people notice when someone is shoeless.
It all depends on whether or not people look at your feet.
The better question is, are they more likely to notice no shoes or the red boots?