The answer is yes! :) Giant thanks to Dennis and Torbjørn T.!
Here I collected and simplified all info to make paragraph separation work.
NOTE: Nothing you set up here will affect the rendered output, just the look of your LyX UI!
Step 1. Setting up margins and a style which will act as the spacer between paragraphs.
Open Document Settings dialog, go to
Local Layout and copy-paste the following:
Press "Validate", then press "Apply".
Step 2. Making enter add the paragraph separating space.
Open LyX preferences dialog, go to Editing/Shortcuts. Search for
break-paragraph, then select the break-paragraph command and click "Modify". Then, in the "function" text box, delete the "break-paragraph" text and replace it with
command-sequence break-paragraph;layout --Separator--;break-paragraph;
Press "Ok", press "Apply" and press "Save".
Step 3. Add option to be able to access the old paragraph break.
Again, in LyX preferences dialog/Editing/Shortcuts, search for
break-paragraph, select the break-paragraph command and click "Modify". Click "Delete Key" and press shift+enter.
Again, press "Ok", press "Apply" and press "Save".
This last step is important, otherwise you would have problems when trying to make an enumeration.
- OK, LyX 2.0.5 on OSX Lion,
- OK, LyX 2.0.0 on Windows 7.
If these steps work with your LyX and you don't see it on the list, please edit the post and add yours!
The original ideas are taken from Dennis's answer (appreciate a lot again!).
I slightly modified the text to be typed into Local Layout, so the separator style does really just make a space between two paragraphs.