1. Yes, if they were to become unavailable or shut down, you could "force close" your channel and redeem the sats onchain after a waiting period.
  2. Yes, without the data on your phone you lose the pre-signed commitment transactions, and can't close the channel at all. You could wait for them to close the channel, but without the data on your phone you wouldn't be able to dispute outdated force close transactions.
There are other censorship risks, too. Not sure about Greenlight, but Phoenix somewhat sees what destinations you are sending funds to, and they could selectively block them. Maybe that's a more realistic kind of censorship that you'd expect to actually see one day.
Thank you for the reply. Yes, good point regarding them being able to censor destinations. I see how this can be another realistic scenario.
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