Actually, there a single real DEX and it is bitsquares, but the problem is that it is too much complex and limits the users.
I don't consider Localbitcoins as a DEX, it is more a marketplace with an escrow, they are not present everywhere, in algeria you can't use localbitcoins.
This is a matter of reputation, they are active since a long time and they built a strong reputation, even if it they still have troubles with some customers regarding withdrawals.
1- Because localbitcoins offers the possiblity to exchange FIATs to Bitcoin directly, and one of the most popular demands regarding this kind of exchange is Paypal.
2- Regarding Poloniex, it is mostly an issue regarding the platform's bots, because sometimes during bitcoin's high/low phases, the bots linked to Poloniex slows down the platform.
Bittrex for example is newer compared to Poloniex, but they earned reputation because they sorted the coins, there are no forks or shitcoins there, and it was one of the first exchanges to add coins like Waves and the reçently strong coins.
One of the poloniex's strengh was the support of XMR and ETH.
Now, could you please check the XRP wallets ? How many users would like to use NVO for Ripple ? How many developers would like to use NVO for their projects ?
About ripple, the 24H volume of Ripple is around $136M, if we can get about 40% of the volume, how many users will be interested to use our DEX ?
ie: if we have 40% of the XRP volume in the NVO DEX, it will bring around $80 USD Weekly, in means that the holders will get $1.120.000USD.
The crowdsale is around $2M, after two weeks all the holders get their funds back. Needless to say what will happen if they keep on holding them.
Most of the wallets are non official, you can check them, some of them are good, but NVO can do better.
Regarding localbitcoins, they don't have a wallet, how about implementing them on NVO using the plugin system ? Both projects would benefit from it.
3- Reputation, innovation, the ability to add new pairs quickly. Because it is not easy to add a new coins and maintain them, there are always wallets on maintenance.
4- BTC-E is a fake volume, their code system is used as a support way by third parties platforms. Localbitcoins is popular because you can use a lot of different payment methods who are not supported by exchanges.
The wallets are customisable, anyone can either create a plugin, or a "mod" for the wallet, like a trading "mod". We will work on the plugins to provide as much "mods" as possible for the different users, everyone will have the basic wallet, and then they could choose a special modes and switche between them.
The most important is the validator, as it will meet the ideas of everybody.
Effectively, we will try to recruit people with a minimum of development knowledge, and the required communication skills, not only for english, because NVO have to be international as it is decentralized.
The main innovation brough by NVO is its mixity, NVO won't be a DEX only, but a complement to the blockchain projects. Not a way to get money out of fees, but a way to join projects together.
NVO isn't a blockchain to be compared with other blockchains as it is not required, except to get more funds, regarding development, it is not mandatory to use a blockchain for a DEX.
It doesn't change anything, what ever happens the most important is to get access to the network in a way or another, from there, you can work your own solution or adapt the existing one.