Here is my question. Is there any good solution here? I don't think that what I want to do is unreasonable, but should I give up and just keep a copy of the widgets in every site folder? Thanks in advance for any help.
<script tag. So if you have several sites and want to access a common /js directory on all of them the work has to be done in the web server itself (IIS/Apache).
/js (or whatever name you choose). Do this for all the sites, and you have one /js directory that is accessible from all the hosted domains.