What is the stylist toolbar? The rich_text_spec contains attribute/value pairs; one can include arbitrary javascript code there (see below for an example). There is no need to source javascript code. Put every javascript for the configuration of xinha there.
The definitions contained in the folder object are used for every page contained in this folder (i.e. for this xowiki instance). The definitions used for the folder object for the wiki on openacs.org are:
set rich_text_spec {richtext(richtext),nospell,optional {
label Content} {htmlarea_p 1} {html {style {width: 100%}}} {
options {editor xinha plugins {Stylist OacsFs} height 350px javascript {
xinha_config.stylistLoadStylesheet('/xowiki/resources/xowiki.css',
{'div.code' : 'Code Block'});
xinha_config.stylistLoadStylesheet('/doc/openacs.css');
}}}}set widget_specs [list *,text $rich_text_spec]
These definitions are passed via acs-templating to the HTML generated for the page. So, if you have added the information to the folder object, and you edit some ::xowiki::Page (a new one or an existing one), you will see the included javascript when you look at the source-code of the currently displayed HTML page.
What is the definition you are using? What do you see in the HTML page? Maybe, the answer to your "problem" is trivial: stylist shows in the panel only the applicable styles. Depending on the provided styles, the panel might be empty.