The hyperlinks on the extensions I tried to download indicate that they are pointing at an .oxt file or similar. When I download them they are .zip files. At least one did not contain any .oxt files or similar. How is it supposed to work?
You should rename the zip file to oxt and open it with the Extension Manager.
some webbrowsers ignore the file-extension and replace it by themselves, thinking they are more clever than the user/the webbrowser. It might also be caused by the webserver using a wrong mime-type. So please post example URLs so we can investigate whether it is a browser or a webserver problem.
I tried commenting above, but only the first line shows. (Then I could not get back to this page for a while.)
One page/exentsion that shows the problem is:
with the download link of: http://extensions.libreoffice.org/extension-center/digitizer-of-xy-chart/releases/1.1.2/ooodoffice_1.1.2.oxt
I have since found that it happens in IE8, but works properly in Chrome Portable.
The problem with comments is that the number of characters is limited and pressing Enter will submit the comment instead of inserting a new line
To insert a new line you need to press Shift+Enter
But you can delete your incomplete comments by clicking on the x (far right of the comment)