Institutional brokers offer DMA too. I would say the "power" of the prop firm is allowing traders to get excess leverage with under $25K, where they can't even daytrade in a customer account.
Yes that's right. But the number of venues tgat international brokers offer is not as big as some prop firms do.
On each ECN official website. List you can find here and links: http://bedaytrader.com/index.php/orders-list