1. Yes, it is proven that binance has very good security and yesterday's incident I think is because there are people in the hacking
2. the average volume there is indeed very high
3. most of the IEOs conducted there have experienced more success than other exchanges because the community there is very large
Definitely they are good in security but even if there is a hack like last time the team reacted very fast and they restore te investor funds which give confidence to the investors which is very important to any exchanges. The higher success ratio for their IEO is as CZ stated earlier they are concentrating on the quality projects rather than the number of projects launching through their launchpad as far as they could. No doubt that Binance has become the Amazon or Google of the crypto ecosystem in my view