Will the Stylist panel display even if there are no 'applicable styles'?yes
I am still struggling with the 'folder object' concept. I have created an ::xowiki::Object and inserted the rich_text_spec definition referenced above into the 'Content' box.xowiki creates the folder object automatically for you. Look into your admin pages, you will find an ::xowiki::Object with the name "::SOMENUMBER" in your instance. SOMENUMBER stands here for the folder_id in the content repository. If you create an arbitrary ::xowiki::Object as you indicated in your last posting, it won't do anything.
Now, does that mean by simply saving this ::xowiki::Object I have 'enabled' the Stylist panel for this and other pages/objecs?yes, if you update the folder object, the definition will be valid for editing all pages of this xowiki instance using xhinha. Note that ::xowiki::Object and ::xowiki::PlainPage don't use xinha, so there will be no stylist.
How do other pages/objects reference this content?Every page of xowiki is saved in the content repository under a folder (which is as automatically created for every xowiki instance). Wery ::xowiki::Page knows its folder (normally the parent_id) and checks for its configuration the folder object.
Hope, this helps