Not exactly. It’s possible to make an app run on older versions (select lower minSdk) and yet take advantage of newer features (select higher targetSdk). This one can be easily be fixed by the F-Droid developers like almost all other developers have already.

Droidify is amazing, I’d totally recommend that over the official F-Droid client any time. 👍

Did you mean “offline” as in not online (which makes little sense for a browser), or more like “not tied to a specific service that may hold your data hostage or infringe upon your privacy”?

If the latter, then I’ve found that a simple HTML file with manually added entries works great. I’ve set it as the home page in all my browsers. I retain full control over content and layout as well.)