I am a ZSA supporter and I hold a significant number of coins. I didn’t vote them, for reasons I’ve explained ad nauseam by now. I’m not going to tell you what difference it would have made to the vote, because that would allow you to calculate my holding, and I don’t hold them in a private cryptocurrency for show. I will say that my vote by itself wouldn’t have influenced the outcome much. But I suspect that there are probably a lot of people like me, and that we might have seen significantly different results if coin-weighted voting were a safe, first-class feature in Zodl and other wallets. (I still would not support the outcome of such polls having more than one-third influence over protocol evolution.)
Absolutely not: the point of ZSAs is that people want to trade a variety of assets privately. I expect most holdings on the Zcash chain would still focus on ZEC — and if the pie increases enough in value, then likely so will ZEC’s share of it. The success of NEAR swaps in Zashi/Zodl has proven that there is a huge appetite for cross-asset functionality on Zcash, and that the resulting interest benefits the ZEC price. ZSAs can make that usage more private.
[Edit: I expanded significantly on this argument here.]