Clicks can take up a lot of bandwidth so it is understandable that they would be of concern.  Same with hum on the carrier.  But chirp or yoop takes up only a little extra bandwidth and I've never felt it was too a big deal for routine contacts.  Actually helps discern one signal from another and gives character, right?  

I'd love to have a time machine to go back and hear how the bands sounded in the decades before I was a ham.  I bet they were more interesting than today. 

The only Official Observer card I ever received was for operating "out of band".  I was on 40m CW with my crystal controlled HW-16 and he was hearing me 455 or 910 kHz away from my actual frequency (I don't recall which).   

Even as a Novice I remember thinking that this seemed more likely a receiver problem on his end than a transmitter issue at my station.  I was in QSO with another station at the time the OO report mentioned, so clearly at least some of my energy was inside the band.

I set up my station to match my logged conditions of that date and time and listened with my Knight R-100 shortwave receiver (my only other piece of gear in those early days) for a spurious out of band signal - nothing heard.  It is not impossible that I had a spurious emission that he heard, but it would be a remarkable coincidence that it was 455 or 910 kHz from the main signal.

If he was having a receiver problem, I bet he wrote a lot of cards that day for all those stations he was hearing out of the band.