I very highly doubt that there is a need for a brand new exchange just for this.
Hmm, that hasn't stopped new exchanges from popping up before. It's a question of marketing and incentives for traders.
Launching the site would require immense trust and advertising. People don't even trust bittrex, bitfinex, and btc-e just got shut down. Why would they trust you?
I'd agree that this is the big hurdle for any new exchange. While the vacuum left by BTC-e does need to be filled, it'll be tough to gain trust.
Charging a percentage withdrawal fee also makes no sense imo.
Considering the position of Okcoin and Huobi in the Chinese markets (as mentioned above) that might not be true.