Try it and see, I suppose. My experience of it is that you can read an individual conversation but if you just look at some random person's timeline it will only show you a few tweets before asking you to log in.
That specific behavior seems to have gone away when musk culled a whole bunch of microservices a couple weeks back. I know well what you're talking about and it annoyed the hell out of me, but now its gone! For now, on desktop browsers, anyway.
Could be desktop. Mobile browsing still seems to trigger demands for the app to be installed followed by login requests, though I just picked a few tweets at random rather than checking systematically.
That seems to not be true. I just made the mistake of not noticing a Hacker News post was to Twitter a few minutes ago, clicked on it, and couldn't even read the Tweet because it was covered by a modal telling me to turn on notifications, which I'd never seen before. What can Twitter even notify me of if I don't have an account? Everything that is ever Tweeted globally? That would probably be billions of notifications a day.