unexpected curtesy clefs and key signatures

Hi, in the attached score I created a single tenor part and when it's rearranged due to editing the text or adjusting the stretch or the page properties, new and unneeded curtesy clefs are inserted in various place in the score, as are unnecessary extra key signatures. Is it a bug or did I miss something?

I also note that while the clefs can fairly quickly be deleted (select, select similar, delete), I haven't found a way to delete the key signatures. I can make them invisible, but that has to be done on them individually.

Similarly, some of the barlines are doubled, as is the 3rd on the 1st line, the 2nd and 5th on the second line. Turns out this is more evident on a printout than on the screen. I think this is also a bug.

Many thanks,
Andrea