What happens when we pass 10% debt ratio and continue to grow past it without no easy way to convert SBD to Steem?
Nothing changes really (in terms of SBD; it does imply a further 50% drop in the price of STEEM which would certainly be painful all around). Since no one is converting SBD the amount of STEEM you would get by converting it is irrelevant. If SBD does drop to $1 or below and it starts getting converted then the ratio would probably drop (eventually).
BTW, the main reason conversion was removed from the UI was people were doing it anyway when SBD was worth $10 and burning 90% of their money. To protect people who didn't really understand what was going on, that option was disabled. However, with SBD back close to $1 it would be reasonable to re-enable it (I'm also told that it is possible to perform conversions using steemconnect for people who don't want to use the CLI).
What happens when freedom decides to sell his 944,780.18 SBD?
The price will drop! If it drops to $1 or below then people will start converting it and the ratio will drop.
Most of the large SBD holders are exchanges and that liquidity is required to maintain their market.
Most likely the SBD held in exchange accounts is actually owned by exchange customers and not the exchanges themselves. Most of it isn't being used directly for liquidity, it is just being held. Who those customers are, what they want the SBD for, what they will do in the future are all unknown.
If SBD remains unpegged to $1 USD, is there any reason to keep it?
As you noted there are improvements already being made in the upcoming hard fork. Also, at a current price of $1.03, I wouldn't consider it to be all that unpegged (this is within the range observed for other decentralized pegged tokens such as DAI or BitUSD). You can take a glass half empty approach and say that SBD going up to $12 proves that pegging doesn't work or half full approach and say that it dropping back down from $12 to $1-$1.20 and staying there for the past couple of months proves that pegging does work (if imperfectly). Eye of the beholder I suppose.
BTW, a large part of why the print rate is zero has almost nothing to do with SBD and everything to do with the STEEM price dropping. When STEEM isn't worth much the whole system is hobbled in a lot of ways, SBD being one of them but hardly the only one.
RE: SBD Print Rate: 0%