What about other kinds of data like bookmarks or history?

One problem that Mac users sometimes experience is that the Firefox application doesn't get successfully installed to the Apps folder, so every day is like groundhog day. As the first step, could you double-check the steps in the following article and see whether you can get it permanently installed?

How to download and install Firefox on Mac

I will. However, the app shows up in my Apps folder; does that mean anything? Thank you for your help!