I've only taken the time to skim this as I'm on my way to bed, but looks to me like you're creating a phantom oversupply by not counting all of the SBD that were printed over the last couple of years as part of the Steem supply. There's also an aspect where printing goes up as the price goes down because SBDs become worth more Steem as part of the Virtual Supply which controls inflation - see this post - but most of what you're seeing is people turning weird-steem-in-a-box (SBD) into regular Steem, but then only comparing it to historic values of regular Steem. It was really Steem all along, just in a rather strange container. So that doesn't increase the supply.

SBD being worth more Steem now than went into them when they were printed increases the supply, but it does that whether we convert it or not.