Hey mammono,
Thanks for your question.
1. By default, Microthemer only applies CSS to the current page you are working on (by creating a separate folder for each page). However, you can customise what pages a folder loads on. It can load on all pages, all single post pages, all post pages which a certain category, etc etc. So if you want the CSS to apply to a defined set of posts, you can use the folder logic settings. See the following video for instructions:
https://themeover.com/load-wordpress-css-on-specific-pages/
2. Use the Targeting switch at the bottom right of the Microthemer interface to temporarily disable Microthemer’s selection of elements. Then, click in the page to trigger the popup. And then turn targeting back on.
Sometimes you may have the opposite problem, where you want to select something without clicking it (and triggering some behaviour). To do that, hover over the element, and press the Alt key (Option key on a Mac).
I hope that helps. Please let me know if you have any further questions.
Cheers,
Sebastian