Using dashboard widget inside UI-template?

This may be too late and I hopefully get what you want right but considering your second question, it could be solved in a way that you put your widgets in separate ui_groups and position them yourself via css.

Here is an example how to position a group (though 'position: fixed' shall be 'absolute' I guess): How to lock the dashboards groups locations

Besides that if you load that css from a file (must be put in the folder defined by httpStatic) via an http template added to the html head like:

<link rel="stylesheet" type="text/css" href="/mystyle.css?id=2313143423423">

by modifying the id you may even be able to force the browser to reload it whenever the css is modified dynamically. However, I haven't tried that so this is just theory.