Short answer: yes.
We created the first extension that does this, openBuild: openBuild is now completely FREE š
And most if not all the ones you mentioned use the same mechanism so I can say that yes, those developers can see basically everything you mentioned. We use the interaction to access the clipboard so you can paste and copy components to and from openBuild.
However, everything you mentioned can more or less be already seen anyway. With or without those extensions.
Have a look at check.tinkso.com and enter your app ID. Pages, workflows, plugins etc are all visible anyway.
Using any tool or service is a risk and the same goes for these extensions, you need to do your die diligence and decide for yourself if the added value is worth the potential risk. Like using bubble itself ā¦