Hi Alan :
The bug you find under your list 4 is an old one. I changed from
Microsoft Word years ago to OpenOffice and I was horrified at the
efforts to prepare an envelope compared with the ease in Word.
When I dropped Windows for linux about 18 months' ago, I moved to
LibreOffice 4.2.8.2 and saw that LO Writer had inherited the same bug
from OO.
My case involved a standard size European envelope to suit A4 paper
folded into a third (two folds on the long side) - approx 22cm x 11cm.
IIRC, this is the DL envelope in LO and OO.
LibreOffice (and OO) give in this case an unwanted 2" top margin. Your
workaround to correct paper size, adjust top margin, shift the text
boxes, is too much hassle if you've lots of envelopes to do.
My 'fix' was to create my own envelope template with the sender's
address filled in and an empty text box for the recipient. Highlight
and copy the recipient's address from the letter before opening the
envelope template and then paste the address into the recipient's text
box and hit print button.
Interesting how these old bugs hang around and don't get killed off by a
cold winter. Much be something to do with climate change.
Philip