Premixing sounds horrible, lets say i own 1000 DRK; all of them get "premixed" ; now i buy something for 1000 DRK with my mixed coins - or i simply send them to an exchange, all inputs will get combined again and its clear that i am the owner of all of them.
It is clear to who? The receiver? Well obviously, if you want something in exchange for your coins lol.
If i send them through Darksend to the receiver, theres no way to cryptographically proof they are from me which is a total no-go for e-commerce; but is easily doable with CN.
Retailer will do what they always do, they create an address for you to deposit. You send coins to that address. Problem? And, you still hold the private keys to the addresses where the coins were sent from. If you need to sign a message with those keys it can be implemented?
To not mix inputs people would have to carefully use coincontrol and be very cautious... absolutely not suitable for the general user.
If darksend is not enforced, no normal people will use it and endanger everyone who wants to stay anonymous.
There is a combo box selection when sending, whether to send anonymous or non-anonymous funds. No need to use coin control. And, the new wallet design is under development, making it easier for people to use should be one of the focused areas, agreed.
Regular people will use SPV/liteweight/zerotrust webwallets and enthusiats will run full nodes, it simply doesnt matter if if the blockchain is 50 or 100gb big in 5 years, thats nothing.
Old tx in cryptonote are getting reused, providing further anonymity. They have a good use, unlike in BTC and co where old tx are useless.
I'm sure cryptonote will be good when it reaches the maturity that Bitcoin codebase offers, whether it's 1 or 5 years. But just like we've seen happening with Bitcoin, unless the newcomer is radically better than an established product, it can't take over.
DRK needs 1000 DRK to run a "mixing" node; how do you expect to scale that, you are actively limiting the anonymity with such design decision, even worse you are creating a 2 class economy, same goes for the mining reward which is based on the Nethash, at some point capping the network security - even worse if 20% rewards will go to the masternodes.
If you talk about scaling, i guess you have VISA kind of scale in your mind, If you think that the masternode stuff will be scaleable to that i cant help you.
Regarding "2 class economy" or rewards, dunno, I'm not an economist, and even if I was, this is something that hasn't been done before, so all talk is just subjective speculation imo.
Regarding scaling, sending doesn't use masternodes. Premixing does. So after your coins have been premixed, you can keep buying stuff from a lot of merchants for a long time until you need to premix again. And, it's not like the design is set in stone, the coin is only 6 months old, and the main dev has said that he will be developing full time at least for 2 more years.