Firefox sync really is neat, but be aware that for the last several years it has had a security flaw, one which the Firefox team has no interest in fixing (in fact, they consider it a feature!): your passwords and other private data are encrypted with your Firefox Account password. That would be fine so long as a) your Firefox Account password is truly secure and b) Mozilla can never see it. Unfortunately, they can: they serve an HTML page to log in to your Firefox account, which loads JavaScript from their servers. At any point they can start serving JavaScript which sends all passwords to their servers.
What is so very, truly disappointing is that they used to have a great, easy-to-use Sync security system which was immune to this sort of attack, but they removed it.
Anyway, I cannot advise using Firefox Sync for private information anymore.
I trust Mozilla to write Firefox and I trust Debian to package it. I do not trust Mozilla to be trustworthy on a live and ongoing basis.
Can I associate one login/password pair with multiple domains?
Anti consumer companies shouldn't get your money.
I agree that what Apple is doing here is wrong, but the alternative is worse on other fronts like privacy which is much more problematic (to me at least) than App Store restrictions.
This is the case of going with the lesser evil.... and there's no way in my mind that Apple would be the greater evil than Google when it comes to tracking users and learning all their habits while using Android.
Apple is not perfect and I hate it for being so anti-consumer when it comes to repairing... and I'd love they would fully commit to a privacy-minded iOS if they have the guts to do it.
Anti-trust regulations on Apple would also be very welcome, but irrelevant to the privacy problem.