Development is pretty rapid too. I didn’t track the features on the updates, but new versions were getting pushed regularly. No mobile app which was kind of a bummer, but the progressive web app integration was pretty good. It felt like a mobile app.
Edit: I forgot to mention the note sharing function, it shares a URL of the note that allows the recipient to view and edit the note through the URL. It was a little janky when compared with sharing a note between two users using themselves app, but it still worked pretty decently.
Those are strange issues, I personally haven’t experienced any of them.
If you’re interested in malware detection, you might try Hypatia.
A reinstall might be helpful, but if you’d like to go back to the original Pixel firmware you can do that pretty easily. First, go to this GrapheneOS installation page and scroll to the bottom for the instructions on removing the non-stock boot key. Then you can use this link to install the stock firmware: Google web flashing tool. It uses a similar web flash tool to what graphene uses for installation.