DarkCoin's system for mixing transactions is CoinJoin, just like Bitcoin's system for mixing transactions. There's no special support for it in the DarkCoin core, it's just a rebranded Litecoin with different mining properties.
Incorrect. Darkcoin uses blake, bmw, groestl, jh, keccak, skein, luffa, cubehash, shavite, simd and echo. If you'll note, none of these are Sha-256 with salsa mixing. Stop spreading disinformation.
Additionally, the efficient algorithms offer much higher stability in GPU cores . . leading to great decreases in power usage. The difficulty retargeting is regulated by KGW. The block generation time is similar. The block reward is dependent on the difficulty.
The capability of CPU mining vs. GPU mining is one of the best I've ever seen with an R9 290 only pulling 10 times the hash of a core i7.
Pretty much the only thing in this coin that is shared with Litecoin is the wallet interface, which was brought into Litecoin from Bitcoin.
Darkcoin and Litecoin are altcoins, but Darkcoin is not a Litecoin.