Alternatives based on peer-to-peer (micro)payments are already staring to emerge, e.g. this guys is building patreon alternative based on Lightning Network (Bitcoin's second layer able to handle millions of tx per seconds for negligible fee):
depends.. Brave has actually got it's own token that could be used to pay creators, not sure how the transactions are logged though but i'd imagine that you can privately pay without being tracked
Yes, but there's always a third party that can in theory collect all your data.
Who? I'm not really familiar with how Brave does it, but there are plenty of cryptocurrencies where that's definitely _not_ the case.
It's still not clear whether untrackable cryptocurrencies will be allowed by regulators.