I am kind agree with you. The only benefit of SBD is flooring rewards for authors. But its cost is quite bigger (i.e. publishing price feed, adjusting witness policy, additional selling pressure when STEEM price is going down, etc.). By removing SBD, we can remove large proportion of complexity.
Pegged asset sounds sweet. But in fact, it is basically a community money as well as STEEM. For instance, ETH person never uses SBD even though 1 SBD perfectly equals to $1, while Steemian is willing to use both SBD and STEEM as a payment method. Volatility is less important than belief in the platform.
Yeah, that is also a good point.
Yes, pegging currencies represent costs. A good example for this in the fx world- is the Swiss National Bank's move to remove the EUR/CHF floor of 1,2 in Jan. 2015, which they have supported before in order to support their economy & exports. They gave it up eventually as the costs were running to high and the pressure on the Euro was to powerful as the ECB was highly accommodative in their policy.